Nuclear Museum Logo
Nuclear Museum Logo

National Museum of Nuclear Science & History

Philippe Halban’s Interview

Manhattan Project Locations:

Philippe Halban is a European biologist. His father, Hans Halban, was an eminent physicist who conducted nuclear research with Frédéric Joliot-Curie in France in the years leading to World War II and then in England and Canada as part of the Anglo-French nuclear effort. In this interview, Philippe provides an account of his father’s life, including Halban’s family, education, and love of science. He discusses his father’s relationships with fellow scientists, including Francis Perrin, Lew Kowarski, and Joliot-Curie. He also describes how his father and Kowarski fled France for England in June 1940 with France’s supply of heavy water to keep it out of the hands of the Nazis.

Date of Interview:
December 14, 2017
Location of the Interview:


Cindy Kelly: I am Cindy Kelly, and this is Thursday, December 14, 2017. I’m in Geneva, Switzerland, with Philippe Halban. My first question is for you to tell us your full name and spell it.

Philippe Halban: My name is Philippe Halban. I usually pronounce it the English way. It’s spelled the French way, with two p’s and an e at the end. My mother was French. That explains my first name. I’m delighted to be able to speak with you today about my father.

Kelly: Just one thing. Could you spell Halban?

Halban: Yeah. Halban is spelled H-a-l-b-a-n.

Yeah. My father’s family on his father’s side originally came from Poland, and moved from Poland to Austria as part of the empire towards the latter part of the nineteenth century. His grandfather was a senior civil servant at the Austrian court, and was the equivalent of cabinet secretary to the upper house.

Interestingly enough, the name Halban is not actually the original family name. They were called Blumenstock, which means a flower stem. The Emperor and his court at the time felt it to be polite and non-polemical—a little sensitive and embarrassing to have their senior courtier with such an obviously Jewish name. They therefore offered him a title, in exchange for his agreeing to change his family name. He was given the equivalent of a knighthood. He was called “Ritter von,” but not Blumenstock. He changed it to any name of his choosing that was not too obviously Jewish, so he chose the name Halban, which is totally invented and, ironically enough, comes from a romantic sixteenth century Polish poem, one of these enormous poems that take up a whole book. Halban was the standard-bearer of a minority sect in this story. It was a little tongue-in-cheek with an allusion to the Jews, but which was not obvious to the court.

Since then, we’ve been called Halban, and the title von Halban. Ritter von Halban. My father dropped the “Ritter” very early on, and he dropped the “von” altogether during the war after the Anschluss [Nazi Germany’s annexation of Austria in 1938]. He was so disgusted by the behavior of the Austrians that he didn’t wish to carry any title related to the empire.

Kelly: That’s great. When was your father born and where?

Halban: He was born in 1908 in Germany, actually, in Leipzig. And spent the first part of his life in Germany, following his father’s career. His father was a physical chemist and had a chair in physical chemistry first in Germany, and then, when my father was a little older, in Zurich.

When my father moved to Zurich, he also did his Ph.D. thesis at the University of Zurich. After that, he moved as a post-doc to Paris but also spent, during that time, which was 1935/1936, a year as a post-doc in Niels Bohr’s lab in Copenhagen. That’s when he started shifting his interest towards atomic physics.

Kelly: His degree was in physical chemistry?

Halban: No. His degree was in physics, but in specific aspect of atomic orientation, as I understand it. I’m not a physicist myself, although I am a scientist.

He very quickly became interested in pure atomic physics. I guess, after he moved to [Frédéric] Joliot-Curie’s lab in Paris and with this post-doctoral year with Niels Bohr. He very quickly assumed, I think, quite a prominent role in Joliot-Curie’s group from ’36 until he left for England in 1940.

Kelly:  Okay. Let’s go back for a minute to his work with Niels Bohr. He was also working there with Otto Frisch, is that right?

Halban: That’s right. 

As I understand it, Niels Bohr’s group was highly focused on the nucleus and nuclear elements. With Frisch in the lab at the same time, there was obviously very active research on the nature of the atom and whether fission could be achieved, and, in which case, what would the consequences of such fission be? That clearly was the main thrust of the work in the Paris group from 1936 through until 1940.

Kelly:  Under Joliot, he was continuing his post-doc? 

Halban: This was in essence his first/second post-doc. He was a junior member of the group. But it’s clear from the publications in Nature coming out in the late ‘30s, as well as the patents that were issued by the French patent office, that there were four scientists involved in that work as co-authors and cited on the patents. Namely, Joliot-Curie, as he liked to be called; Lew Kowarski; Francis Perrin; and my father, Hans Halban. There were four major co-authors of this work. But clearly, Joliot-Curie was the head of the group.

Kelly:  Can you tell us a little bit about Joliot-Curie and who he was?

Halban: I can’t really tell you anything at all, other than what I’ve learned from the literature and also from looking at my father’s correspondence throughout the war with Joliot and my father’s diaries, which outline very clearly his relationship with Joliot, very close relationship. Throughout the war, they continued to be in contact to the best of their ability, given that Joliot was in occupied Paris, and my father was first in Cambridge, UK, and then in Canada.

There is indirect correspondence. It was clear that my father was doing his best to make sure that Joliot received food packages and every kind of comfort that my father could possibly offer him. The exchange of letters in this quite lengthy correspondence was entirely cordial.

Indeed, my father, in his correspondence with many colleagues after the war, despite the fact that he and Joliot were no longer getting on at all well and he was not invited back to Joliot’s lab at the end of the war. There was a breakdown, for reasons that I think we now understand. He always makes it very clear that he regretted this very deeply, because he considered and continued to consider Joliot a very close friend and esteemed colleague.

There was a kind of delicate and sensitive relationship, which was originally based on total confidence and admiration and friendship.

Kelly:  Would you say the complications in their relationship related to the wartime secrecy?

Halban: Yes, as I understand it. Again, I never spoke directly about this with my father. He died when I was too young. I did speak about it at some length with a French colleague of my father’s, Bertrand Goldschmidt, who wrote a brilliant book about this period of nuclear research and specifically the French contribution, and who was recruited to Montreal for the Anglo-French nuclear effort under my father’s leadership—initially, at any rate. My father recruited him, and he was also a friend of my mother’s, so there’s a kind of family link. I met with him on several occasions after I moved to Geneva in the ‘70s. He explained in some detail what had gone on, and I think in a very objective way. 

The main reason for Joliot’s hostility towards my father at the end of the war—this is 1944 to 1946—was because he felt that my father had let down his commitment to Joliot’s group and to the French government. That he had shared too much information with the English and, indeed, the Americans, which, as we now know, was absolutely not the case, because there was no communication between the Americans and the Anglo-French effort. Whereas, my father had undertaken to always represent the best interests of the French government and to defend the patents throughout his time in exile.

Joliot felt that he’d been let down. He also felt, as I understand it, that whereas the original agreement for these patents with the French government had led to the four lead scientists named on the patent only having a 5% personal interest in any fees coming out of the patent, with 80% going to the French government, specifically in support of nuclear physics research. He had understood that my father had negotiated during the war, notably with the English, such as he would then have got 12% rather than 5%.

Is this true? Was my father greedy? I don’t know. It would rather surprise me. I knew him as a very ambitious and occasionally intolerant person. A wonderful father, but he had his moments. He was, however, recognized both in the family and also, I now see from all the papers that I have by his colleagues as well, as an extremely generous and caring man, who was deeply committed to research.

As Bertrand Goldschmidt says in his obituary and I think in the book, too, my father supported with his own money the salaries of several of his colleagues, but never let it be known that he was providing the money. It would slightly surprise me if my father’s efforts with regard to the patents and the British government was simply to get more money. It doesn’t really make much sense.

Did he sell the French short? According to everything that I’ve seen, that was not the case.  On the contrary, it was the English and the Americans who were kind of hands-off on anything to do with the French, because they didn’t want to recognize the French contribution.

It’s all a little bit gray zone-y, but I think that Joliot had misinterpreted what my father had been doing. I can quite understand why he misinterpreted in that way. That’s being as objective as I can, based on the anecdotal information that’s available to me.

On my father’s side, he was initially offered a job in Paris by Joliot, and he turned that down. I think he turned that down because he already felt that Joliot was no longer trusting in him.

Kelly: This was in 19—

Halban: This is in 1945. That was one reason. The second reason was that he felt he wasn’t going to be given enough independence and recognition for his work during the war and that he would be going back to square one as a post-doc, in essence. He didn’t want to do that. He was a proud and ambitious man, so there was a bit of that.

Also, the American government, thanks to General [Leslie R.] Groves, refused to allow my father to return to Paris throughout 1945, because he considered him a security risk. He was trapped in the North American continent, initially in Montreal. Then, with my mother, they moved to New York. He couldn’t go back to assume any position in France.

Kelly: Until after the war?

Halban: Until some time after the war. It was late 1945, early ’46 before he returned. By that time, [Frederick] Lindemann in Oxford had offered him what was a very attractive job, so he gave up on France—I think with some bitterness—and moved to England. He was very happy in Oxford for eight years or so, until he was called back by the French government to start up a lab and to develop the first reactor near Paris.

Kelly: Wow. That’s wonderful. A nice precise of what he did from ’36 to ’46.

Let’s go back, if you’re willing, to talk about some of the drama of early in the war when he had joined Joliot in ’37 at the Collège de France, what they were working on, and with whom he was working.

Halban: As far as I understand it, the work was, first of all, entirely theoretical. In fact, all of the groups—[Enrico] Fermi included, Frisch included, Bohr included—in the late ‘30s, it was still entirely theoretical. The focus was on the atom, the properties of the atom, and the properties of nuclear elements 

As far as one can see from the literature, at more or less the same time, after the initial observation of nuclear fission by Frisch, both the Fermi lab in Chicago and the Joliot-Curie group in Paris independently calculated the amount of energy that would be released by the fission event and determined that the energy was sufficient to lead to a chain reaction that would, in turn, release an extraordinary amount of energy. Bertrand Goldschmidt, in his book and obituary of my father, actually mentions the figure, the number that they calculated, which he says was extremely close to reality.

The French group really understood what was going on. On the basis of their observation of a chain reaction, they understood that the energy had to be contained, focused on the use of heavy water for containment, and issued through the French patent office a series of five patents—three or five—which focused, for the most part, on the production of energy from a chain reaction, but which I think also made allusion to the possibility of a weapon. But the main thrust of their work was nuclear energy and that remained the focus of my father’s work throughout the rest of his career.

His relationship to the bomb is actually quite far removed, especially given the fact that he wasn’t allowed to work on the bomb whatsoever during the war based in Montreal. That, in fact, was in retrospect probably a relief for him. It was never, from my conversations with him, of any direct interest to him in his theoretical work. Morally and emotionally, I think he took a fairly firm position regarding the atom bomb and the H-bomb as a dangerous and politically—obviously politically—highly charged development.

Joliot-Curie, who was an admitted communist during the war and joined the party, was always very, very vocally against development of an atomic weapon. Those were two reasons for his being completely removed from the French atomic effort, as from 1950 or ’51.

There was a lot of political motivation and mischief going on throughout this period, which made the science actually very difficult.

Kelly: I assume that it was part of Groves’ aversion, shall we say, to having further conversation between your father when he was in Montreal and Joliot in France, that he worried Joliot was, as a communist, collaborating potentially with the Russians. Nobody knew where Joliot stood. 

Halban: Exactly.

Kelly:  He may be collaborating with Vichy France.

Halban: That’s right. I think there were two levels of mistrust from Groves’ side. As a general, he obviously had the country’s security at heart, and he was also central to the Manhattan Project.

He felt throughout the war that my father was not to be trusted. First of all, because he was French, and the French had capitulated, which obviously, to an Army man, wasn’t a particularly worthy way to go. Not only was he French, but he was also Austrian, and clearly to someone like Groves, with his education and mindset, “Austrian” meant “German,” because he obviously speaks German. Austria had been taken over without much resistance, to put it mildly, by Hitler. Therefore, anybody who was Austrian was basically German, and anybody who was German was a Nazi, so that was no good.

You can’t have somebody like Halban in charge of a group working—albeit not directly related to the Manhattan Project, but, nonetheless, right next door in Montreal with access to uranium and with access to heavy water and in communication with Fermi. All of that I can understand, if you put yourself in Groves’ shoes, was pretty nasty. I mean, people like Groves want things to be simple and straightforward, and this was not simple or straightforward. This was messy, and he didn’t like messiness.

He kind of put my father to the side and had him replaced as director of the lab towards the end of the war and prevented him, as I just said, going back to Europe basically throughout 1945. There, probably, because of his suspicions of Joliot as being a communist and a foreigner. He was French, he wasn’t American or English, and therefore not to be trusted.

I think you’re right on both counts: both because my father was Austrian and, therefore, not to be trusted, and because Joliot was French and a communist to boot and, therefore, couldn’t be trusted.

Ironically, while Groves was obsessing about my father in direct contradiction to everything that the senior scientists in the Anglo-French effort were saying—including [John] Cockcroft, including [James] Chadwick, who were all fully supportive of my father. It was only Groves who went against him. While he was obsessing about this, there was a spy in their midst.

There was a spy in Montreal called Alan Nunn May, who went over to the Soviets at the end of the war with all the information, including from his visits to the Fermi lab in Chicago. He took everything with him from Montreal and from Chicago.

Under Groves’ careful watch, Klaus Fuchs was embedded in Los Alamos and went over to the Soviets as well. He would have been better spending his time and energy and anger and directed it against the spies in his own midst, rather than these two individuals who were clearly not doing anything untoward towards the U.S. government, or indeed the Allies. It’s funny how these things work out.

Anyway, that’s Groves, and that’s what made the Anglo-French effort difficult scientifically, because they weren’t allowed to gain access to the materials or information that would have allowed them to advance more rapidly.

The other political side to the whole story regards the patents that the French took out, which were never recognized by the United States. Throughout the 1950s, according to the papers that I have in my files, my father made every attempt through the U.S. courts and the U.S. Patent Office to get the French patents recognized, and they never were. The final decision was I think in 1958.

There was an appeal. The appeal was rejected. So there was never formal recognition of the patents, and, therefore, the French government never derived any financial interest from the discoveries that the French team had made, despite the fact that the discoveries were truly seminal, groundbreaking. That’s the way history goes. Governments have to defend their turf.

Interestingly enough, the U.S. government in 1968 through the Atomic Energy Committee—is it committee, AEC?

Kelly:  Commission.

Halban: Commission. Through the Atomic Energy Commission, ended up recognizing the contribution of the French group, and awarded a prize posthumously to three out of the four—Kowarski was, I think, still alive at the time—in recognition of their contribution.

The patents weren’t accepted, but, at the scientific level, the contribution was accepted as being major. From an academic and scientific point of view, that was a nice thing to see. Albeit my father was, unhappily, already dead.

Kelly:  Why don’t you just explain what that contribution was briefly?

Halban: I’m not sure that I can other than that it was, as I understand it, ostensibly one of the first—so the first or the second—clear demonstration of a chain reaction and of the energy that such a reaction could emit, and, in turn, how that energy could be contained and be put to good use in a nuclear reactor. That was the central core of the discovery and the patents.

Obviously, the French government stood by their group and stood by their patents, and felt they had—they, the French—demonstrated for the first time the possibility of a chain reaction and of the energy that could be derived from such a reaction. They even produced a medal, which I have and I’ve shown to you and we can photograph it, commemorating that event.

On one face of the medal, you see a list of all the Nobel Prizes from the beginning of the twentieth century through until Joliot-Curie’s prize that contributed towards our understanding of nuclear physics. You see a series of profiles of the scientists involved. The only profiles that you can clearly distinguish are of the four French scientists, so Joliot, Perrin, Kowarski, and my father.

On the flip side, you see a rather nice design, and on top of the design, it’s mentioned, “Chain reaction,” with a date, 1939, and the name of the four French scientists. The French had no doubt whatsoever that they were commemorating a major French discovery.

Kelly:  What was the date of the medal? 

Halban: I don’t know. It’s not on. I think, presumably, sometime to the extent that my father had it—I remember it being in his house—it must’ve been during the ‘50s that they minted this medal.

As a scientist, what I find to be a fascinating anecdote and new twist to the story that came out just a few years ago. When my father moved from France to England in 1940 with the world stock of heavy water, he was set up with a lab with Kowarski in Cambridge. They continued to work very actively, continued their research in Cambridge, and obviously came up with some quite important and remarkable findings that they put into a manuscript that they wished to publish. 

They showed the manuscript, as they were obliged to do—after all, we were in the war and, what’s more, they were foreigners—to Chadwick, the Nobel Prize laureate who was in charge of the entire research effort in that domain.

He said, “Look, this is fantastic science. But we’re in a war and this can’t be published because it’s too sensitive. So here’s what I’m going to do. The war’s going to end one day. I’m going to take the manuscript, I’m going to put it in an envelope, I’m going to seal the envelope, I’m going to sign over the seal, and I’m going to deposit it with the Royal Society in London. After the war, the envelope will be opened, your manuscript will be found, and it will then be published and dated back to 1940, regardless of the year in which the envelope is opened. That way you get scientific priority.” 

Despite the fact that Chadwick, notoriously, was totally uninterested in scientific priority and only in the science. But he recognized that scientists do care about this sort of thing. That was nice.

Nobody remembered that. Nobody knew anything about it. For some reason, neither my father nor Kowarski remembered either. At the end of the war, nobody went to the Royal Society and said, “Hey, could we have this envelope, and we’d like our manuscript back.” Nobody did anything.

I think it was just five or ten years ago that I came across a little piece in Science, the magazine, and on the BBC, saying that on the seventy-fifth anniversary or something or other, the Royal Society was cleaning up their archives and came across this envelope sealed and signed by Chadwick.

They opened it up, and they found a little letter from Chadwick explaining, “Whoever opens it”—a bit like a message in a bottle, right? “Whoever opens this letter, this manuscript should be dated back to 1940.” Obviously, that was no longer possible, but it’s extraordinary.

The manuscript was shown to scientists at CERN here in Geneva, who said that it was an extremely important, visionary, seminal discovery. There we are. The science was clearly very good.

Kelly: Amazing. I noticed, visiting CERN yesterday, that Francis Perrin’s photograph is among these many, like fifteen scientists, including Niels Bohr and [J. Robert] Oppenheimer and others. Can you tell us a little bit about him, since he was so integral to that paper and the other work with Joliot?

Halban: Francis Perrin, P-e-r-r-i-n. He was obviously an important member of the team, working under Joliot-Curie in the ‘30s, alongside my father and Kowarski. They are all cited on the patents. Their names figure, including Perrin, on the medal I just spoke about and, indeed, on the patents. Perrin would have been one of the four scientists deriving modest financial benefit from the patents had they been recognized.

During the latter part of the war, Perrin worked with the free French in London under [General Charles] de Gaulle. Immediately after the war, he was the first Chair of the French Atomic Energy Authority and is considered, to this day, the father of the French bomb, “the father of the French nuclear deterrent,” as it’s euphemistically called. He was in charge of the whole body of research leading up to the development of the French bomb in his capacity as Chair of the Atomic Energy Authority.

He was also, as I understand it, supportive of my father’s call back to France by the Prime Minister at the time, [Pierre] Mendès-France. This was in 1955, ‘54/’55, which my father accepted and moved from Oxford back to Paris and was in charge of the laboratory in Saclay, just outside Paris, where the first French nuclear reactor was developed.

It’s a nice end to the story, as far as my father is concerned. Perrin was really central to this entire effort and was a brilliant scientist. Not only highly regarded, but I think well-liked by everybody. It’s entirely fitting that his photo should be in CERN.

Kelly: The laboratory that your dad worked in Saclay, was part of that research for the bomb or not?

Halban: No.

Kelly:  No.

Halban: He was an academic and his work was entirely theoretical. As I understand it, he was not directly involved in the work leading up to the first test of a French nuclear device. That’s my understanding. I may be wrong. 

Kelly: Great. This is very helpful. I’d love to get whatever story—maybe anecdotal in the second-hand, but that’s what we have—about the whole escape. If you could start from France in 1940—

Halban: Yeah. That I do know a little bit about from chatting with my father as a child and from his diaries that I have. I have the copy of his diary from 1940 through until the end of the war. The one from 1940 is actually quite detailed. I also have a copy of his marching orders from the French government, allowing him—or telling him and Kowarski to leave France.

It all happened very, very rapidly in June of 1940. Literally within a day of the Germans arriving in Paris, they were already on the boat from Bordeaux to England with the stockpile of heavy water that the French government had got from Norway and had been keeping in Paris. It was now, obviously, not the place to have the heavy water stocked, and it was clearly not the place to have the scientists doing their work.

In the stories that are written about this in the books that I’ve read, at any rate, we’re told that Joliot-Curie was in Bordeaux and at the last minute decided that he wasn’t going to go [to England], in a kind of heroic last stand. It looks as if it was a little bit more careful and thoughtful than that, because the marching orders only mention my father’s name and Kowarski and their wives and their children, but not Joliot-Curie or his family.

He had clearly been in contact with the French government and said, “Look, I’m not going to leave because I think my place is here, even if the Germans are here. I think this is the best way for me to defend the French cause. But I do want Halban and Kowarski to leave with the heavy water.” He was entirely agreeable and supportive of their leaving. He wanted them to leave, but he didn’t want to leave himself.

They boarded this coal ship, which looked like a pretty rickety affair. My sister, who was one or two at the time, sat on the canisters of heavy water, or so she believes. She was obviously much too young to remember, but she always told everybody this story with great pride. They were guided in this enterprise by a flamboyant English earl, the Earl of Suffolk, and they reached England.

According to my father’s diaries, their reception was very warm from most of his scientist colleagues, but less than lukewarm from several members of the government. Notably, civil servants, just like Groves, considered Kowarski, who was a huge, rather imposing, clearly non-Englishman, and my father, with a suspicious name and origin, to really be under suspicion.

They were clearly led to understand that they were secondary to any serious research effort that the English were undertaking, and that their contributions to nuclear physics [0:48:00] were certainly secondary to anything the English had done. It was a kind of pretty nasty atmosphere at the official level, but extremely collegial and welcoming at the scientific level.

Kelly:  Who were some of the more welcoming scientists?

Halban: Foremost amongst them would be Chadwick and Cockcroft at the same time. Rudy Peierls was in Cambridge at the time, later in Oxford. I remember seeing him on several occasions. My father and he hit it off. My father certainly had great respect for Peierls and, probably, that was reciprocated once they’d understand what the French had been up to.

It should be remembered that the French work had been published in Nature. They had three more or less back-to-back papers in Nature, which the English had obviously read. They had been to scientific meetings. They knew each other. 

The hostility of the civil servants was actually totally misplaced, but it was so extreme, their mistrust. I remember my father telling this extraordinary story. He had to drive from London to Cambridge a few weeks after arriving in England to start his work there. He didn’t have a map of England, and no maps were available or made available to him because he was suspect. I guess the civil servants thought he was going to send a cable to the Germans telling them how to get from London to Cambridge. I mean, it just seems totally, totally absurd.

Anyway, he had no map, and he was given to memorize a list of pubs. The way he was supposed to get from London to Cambridge was to go from village to village, asking for the name of the next pub, because it was supposed that the people living in these various villages would know the name of the pub in the neighboring village. You could hop from stone to stone, and from village to village, from pub to pub, until you reached Cambridge.

Their mistrust was extreme and absurd. That went on, basically, throughout the war.

In addition to there being no maps, street signs had apparently been taken down, according to Bertrand Goldschmidt in his book. Again, making it almost impossible for somebody who wasn’t familiar with a town or a city, let alone had to get from one to the other, to make his way around the country.

They were under deep suspicion. But despite that, I think my father had a successful and exciting scientific time, however brief, in Cambridge before moving to Montreal. Certainly, he gained sufficient trust from his scientific colleagues to have been given the leadership of the Anglo-French effort in Montreal.

Kelly: Tell us what was going on in Montreal. What was the objective?

Halban: As I understand it, the objective was not to develop a weapon, even if this was part of the so-called Tube Alloys project. The focus of the Anglo-French effort in Montreal was to continue the French work on the chain reaction and to use heavy water as the containment element for development of a nuclear reactor.

That’s what they were supposed to work on. Whether or not they managed to do serious work in this particular field in Montreal, I don’t know. All I do know is that from what I’ve seen from the correspondence and from the diaries, the Anglo-French group in Montreal weren’t given access to the materials or to the information that they would have needed to advance their research in a timely fashion.

I think they were kind of bogged down by bureaucracy and by the problems surrounding any research effort in the war. I don’t think anybody’s to be blamed for that. I think just those were the circumstances.

Kelly:  Your dad was initially the director, and then what happened to change that?

Halban: The official story line is that Groves wanted him replaced as director of the lab because he had no confidence in him. I think there was a hidden storyline that he wasn’t considered by all his colleagues or by the Canadian government as a particularly able director or an administrator.

I don’t think his science was questioned. But I think the way he was leading the lab and his administrative skills were put into question, from what I’ve seen from the correspondence and the documents. Which was the guiding lead factor? I don’t know. There clearly were troubles. I don’t think that it was a group of happy campers.

Kelly:  He did have one trip to London, and then a side trip to Paris to see Joliot?

Halban: Yes.

Kelly:  At a time that Groves was trying to contain his movements.

Halban: Yep.

Kelly: I don’t know the chronology. Maybe you could help. Was he removed from director after that meeting?

Halban: Honestly, I don’t know. It is true that he went to London, I guess, in summer or autumn of ’44, I think it was, and went to Paris and met with Joliot. I have letters between him and Joliot at that time. The relationship was, at that point, entirely collegial.

That’s the irony. My father went in full respect of his commitment to the French, in order to debrief Joliot on everything that they had been doing in Montreal and to keep him fully up to speed. Groves saw this as my father divulging state secrets, despite the fact that Joliot was part of the effort even if he had stayed in France.

Was it on this occasion that Joliot first started to think that my father hadn’t represented their cause as well as he, Joliot, thought he should have done? I don’t know. Or did that come a few months later? But certainly, that visit happened. For my father and Joliot, that was considered an extremely important moment to update Joliot on everything that had been going on.

I’ve never really understood how the relationship broke down to the extent that it did between my father and Joliot. Hard to tell.

Kelly:  Let’s back up a second and talk about another character in this story. Lew Kowarski. What can you tell us about him?

Halban: Kowarski was, I think, of Polish [actually Russian] origin. Again, to go back to Groves and to the British civil servants, my father was Austrian, but Polish going further back. Here was Kowarski. All this “Mitteleuropa,” as we call it. All these figures from deepest central Europe were clearly suspicious.

Kowarski was clearly working side-by-side with my father in Joliot’s lab. Thereafter, they took the boat together from France to England, worked together in Cambridge, wrote this manuscript together that was discovered so much later in the Royal Society archives, went with my father to Montreal. Clearly, they were very close colleagues.

From what I recall as a child at home, I don’t think my father held Kowarski in the highest esteem, and often made slightly disparaging comments about him. Despite that, they clearly worked together as colleagues. Kowarski went on to have a highly distinguished post-war career in Geneva and was one of the founding fathers of CERN. He was clearly a distinguished scientist.

He maybe had slightly less sophisticated social skills than my father and many of the other colleagues, including Bertrand Goldschmidt, who were more worldly. That had nothing to do with their science. Simply, their social skills and the way they interacted in society with civil servants and with their colleagues that maybe made Kowarski a little more difficult to fathom. I would put it down to that, rather than anything more significant.

Kelly: That’s interesting. I think that Goldschmidt talks about how over time, having associated with Joliot and your father and then after that, whatever rough edges he had, whatever disadvantages he had from not having had such a sort of well-to-do upbringing that made him at ease socially, he became more and more socially adept.

Halban: I’m sure that’s right. I’m sure that’s right.

I never met him [Kowarski]. I did meet his widow when I moved to Geneva in the 70s. She was still living here, and she invited me to tea, and we had a very nice time together. I didn’t detect anything untoward, certainly, in her reaction towards me. She was kind, generous, and open.

Just as you say, I think he was one of these scientists, and as a scientist myself—albeit a biologist not a physicist—but I recognize this amongst my colleagues. There are those who are very able in promoting their science and their cause, and there are others who are withdrawn and maybe more complex in their interaction with the outside world. That doesn’t make their science any the less interesting or important. I would put Kowarski—I hope objectively—in that latter category.

Kelly:  He obviously was recognized over time.

Halban: Absolutely.

Kelly:  Yes.

Halban: Yeah. Yeah.

Kelly: That’s great. Thank you for that. Let’s see here. Do you know this code that Joliot used to describe your father and Kowarski’s going to England with heavy water? Do you remember what he said?

Halban: It’s funny. At the time just after my father and Kowarski had left France and arrived in London, Joliot-Curie sent a cable. Obviously he was concerned that people would understand—notably, the Germans—what had been going on. So he said, “H and K have arrived with the gloo-gloo.” “H and K” is “Halban and Kowarski,” and the “gloo-gloo” is, presumably, heavy water.

I have no idea where that particular kind of jokey slang came from. Was it the word that they used within the lab in a kind of jokey way between themselves when they were referring to heavy water, or was it something that Joliot thought up on the spur of the moment? Who knows? But kind of funny anecdote.

As I understand it from my father’s diaries, which as I said are very personal, very detailed, and also scientifically quite interesting. He comments both on kind of day-to-day activities, as well as meetings with senior government officials, including [Sir John] Anderson, Chancellor of the Exchequer, who was responsible for the whole project. Also his other colleagues. 

He very often mentions those who were welcoming, open, and kind, in particular, Chadwick. But also the other senior members of the Cambridge team. How much pleasure he got both as a human being, but also as a scientist: being able to share his views, share his experience, share his results, share his thinking with what were, of course, the leaders in the field who he had met at scientific meetings but had never had the occasion to discuss with in such an intimate way.

Chadwick, in particular, was clearly friendly, warm, and supportive from the first day and throughout the war. When he first moved to Cambridge, Chadwick was always there, always supportive, always listening to him, always putting the French results on a pedestal, rather than the exact opposite, which some other Englishmen were doing at the time. Clearly supported their work. Clearly thought what they were doing in Cambridge was important.

My father was very deeply concerned about Joliot’s fate and his family in Paris under the German occupation, and asked of his colleagues and of the government officials very frequently. I mean, basically at every meeting, “Have you heard from Joliot? Is everything okay? Is there anything that we can be doing to make sure that he’s all right?” After all, he was a scientist under occupation, working in a field of considerable interest for the Germans, as we now know. He could have been treated very badly. As it happened, he wasn’t, as we understand it, but my father was very concerned about that 

Kelly:  That’s great. Now one other thing from his diary that I think is worth mentioning, where he talks about: “We saw the whole of English society as outsiders, probably better than the English themselves.” This was in the context of looking at the British attitude after the fall of France. He summed it up, “We [the British] will not go down without a fight.” He said he got this impression from the porters, from the bellmen, from a whole swath of the society. If you can remember that from the diary and maybe tell us a little about it.

Halban: I think anybody living in those times in England would have quite naturally deeply resented the French capitulation, and the fact that they surrendered and were overwhelmed by the Germans so rapidly, leading to the retreat of the British forces from Dunkirk, and kind of legendary British resilience. One can understand that the British would see the French as being kind of lily-livered and cowardly. Here were these two foreigners. Even if they had a French passport, they weren’t really French. But they came from France, and my father certainly had a French passport; Kowarski, I’m not so sure.

You can imagine, I mean, even talking today with a London cabbie, a London cab driver, they’re pretty outspoken. I’m sure from every level of society, from that all the way up to the upper-classes, which my father moved in, so he moved in all circles. He had friends from France outside of science, who he surely saw in London. The English side of his contacts, who were kind of upper-class. At the same time, he met with porters and taxi drivers or whatever. He probably heard the same story from everybody, you know. “What is it with you French, that you just give in?” 

My father picked up on that. I think he probably understood it, but certainly resented it when civil servants and some of the scientists put this all into a great big package. “The French surrendered. The French are cowards. French science must therefore be in some ways second-rate and cowardly, and should be discounted.” It was all put into a great big amalgam, which was unfortunate and probably made my father feel a little uncomfortable.

I think despite the fact that he was exposed to suspicion by many English because of his origins and because of the fact that he came from France, at the same time, he had been horrified—literally horrified, not just disappointed—by the capitulation of the Austrians towards the Germans, and was clearly deeply upset that the French had been forced to surrender so quickly and that the Germans had taken over the country and arrived in Paris very rapidly in 1940. That was clearly traumatic to everybody, but certainly to him as an Austrian émigré, who went to France, and then the whole thing repeats itself, in a sense. 

Then going to England and seeing this admirable resilience, which clearly caught his attention, that he admired, and that, to a certain extent, fascinated him. At the same time, he was being put under suspicion by the English, but, at the same time, he was admiring the resilience. “This is where it’s going to happen. We’re not going to surrender. We are going to win this war.” You couldn’t not but be impressed and overwhelmed by that sort of attitude. Again, at all levels of society.

My mother was born Aline, A-L-I-N-E. De Gunzbourg was her maiden name. She was French. She was actually born in London, anecdotally, but she was French. Her mother was French from Alsace, and her father was Russian. She came from a Russian-French Jewish family on both sides. She was raised in France.

She was a great golfer; she was a French champion of golf. She married very young, when she was just eighteen or nineteen. She had a son, my half-brother, Michel, and her first husband died of cancer a couple of years later. This was by then 1939 or so. My mother was born in 1915, so she was very young, had a child, young boy, was a widow, was a Jew, and the war started.

She moved from Paris with her family to the south of France under the Vichy government. She actually said that she really enjoyed that period of her life. She was very competitive and had considerable initiative and was frightened of nothing.

She had to drive to Vichy to get her exit permit. Drove back to Biarritz, where she was based. Got all the paperwork done through a friend, who was Argentinian ambassador to France. Got out through Spain and Lisbon. Took a boat from Lisbon to New York.

It was in New York that she met, through common friends, my father. They married during the war. She moved to Montreal with him, and my brother [Peter] was conceived in Montreal and born in New York in 1946. She moved back to Oxford with my father in 1945/’46. I was born in Oxford in 1950. My parents divorced in 1956. My father moved back to Paris in 1955 just before the divorce to take up his new job at Saclay.

My mother, who was, as I said, an extraordinary woman from many points of view and a wonderful mother, went on to marry again. Widowed, divorced and then married again the British philosopher, Isaiah Berlin, and they lived together in Oxford until their deaths. That’s my mother.

Kelly:  Did you stay with your mother or your father?

Halban: I lived in Oxford with my mother and stepfather, and visited half of every holidays with my father. First in Paris, and after he had to leave for health reasons, he stopped working in Paris in the early ‘60s. His last years until 1964, when he died, were spent in Switzerland, where he had a house. I went there every holiday.

Kelly:  As a biologist—he had heart issues. Bertrand Goldschmidt said he was an excellent skier. Obviously, as a youth or a young man, he was very athletic.

Halban: He was a wonderful skier. He even had his ski teacher’s license, and he won racing cups, one of which I still have.

He had a heart condition, which was probably congenital, with a problem with one of his valves. I suspect the aortic valve. Even in the 1930s, he had some sort of symptoms of that valve problem and lived with those symptoms throughout the rest of his life, until he was operated on in Paris at the American hospital in 1964 at a time when heart valve replacement surgery was in its infancy. Although the operation itself, I think, was successful in replacing the valve, he got a horrid systemic infection and died a couple of weeks after the operation.

I remember as a child, one often wants to emulate one’s father. Had he been a fireman, I probably would have wanted to be a fireman, but he was a scientist. So I decided at an early age I wanted to be a scientist. 

I remember very clearly talking with him about what it was like to be a scientist, what research involved. I remember him telling me that if I wanted to be a scientist, I would have to be very good at maths and would have to learn German. This was in the 1950s at a time when, certainly in the hard sciences—he assumed, I suppose, that I was wanting to be a physicist—that maths would be important. I was terrible at math, always was, which is why I took biology because it required less math. At the time, German was the major scientific language, and I failed to learn German either. But, luckily, English took over as the major scientific language, so I was okay. But he was passionate about science.

On a more personal level, clearly regarded as a very charming man. He adored music, classical music. As children, he took us to the Salzburg Festival, at a very young age to go to wonderful operas. Always had music on, mainly chamber music, at home from the early hours. Always took his bath listening to [Franz] Schubert, chamber music.

Loved art as well. He was passionate about art. But really passionate about science. Really inspired me as to what science had done for him as a person, and what science could do for society.

Kelly:  Do you want to elaborate on that, what science could do for society? How is that manifested from his work?

Halban: We never spoke about the bomb or indeed any details of his work. I knew he was a nuclear physicist, and I knew about the chain reaction, and I knew that, obviously, there had been the development of a bomb. But I never regarded my father, from the discussions and from my memories I have of him, as having been central to that particular effort, the development of working on the bomb. We never spoke about it.

He did communicate very clearly how exciting it was to discover how the world works. How fundamentally important it was for human beings to pursue that understanding of the world. To ask the right questions, and how exciting it was to get the answers from one’s own research. That I remember very clearly.

He was right. It is exciting. I think I’ve derived the same sort of excitement and fulfillment from research as he did. I think from reading what other scientists have said about him, even if some have commented on his administrational skills or lack thereof—sometimes he could be a little impatient and overpowering. But all of them seem to say that he was a visionary and communicated his enthusiasm for science to his entourage and to his colleagues, particularly to the juniors.

Kelly:  Particularly to whom?

Halban: To the juniors in his group. At least that’s something that I would really like to believe, because that’s the side of him that I saw as his child.

Kelly:  What would you say to young people today about going into science?

Halban: What I would say, and what I do say, is that it’s the most fantastic profession one could possibly imagine, because it gives one complete intellectual freedom to pursue one’s interests, to try to answer fundamental questions. It’s actually a great luxury to be able to do throughout one’s professional life exactly what one wants to do, and to gain such enormous satisfaction. I would say that. It’s really exciting. It’s really fulfilling. It’s fantastic. I can think of no better profession.

There is a but, and it’s going to sound a little bit arrogant, but it’s the truth. I’m not speaking for myself. I can only speak for others and my guidance to others. There’s no point in doing it unless you’re very good. Particularly nowadays when in cell and molecular biology, which is in a sense today what nuclear physics was in the ‘30s, ‘40s, and early ‘50s. It’s kind of one of the lead fields in science.

It’s so competitive that if you want to succeed—and only in succeeding will you be able to derive any personal satisfaction—you have to be good. You have to have your eyes open and you have to be very honest in your self-assessment. If you’re not going to be at the top, then go for something else. Use these same skills, but in another environment. Not as a group leader or a scientific director in your chosen field, because that’s doomed to failure and you’ll be miserable.

Kelly:  Well, that’s very honest advice.

Halban: That’s what I tell the young. Some of them follow it, some of them don’t. Some of them succeed, some of them don’t. Some of them are happy, some of them are not. That’s the way it goes.

Kelly:  Looking back on your dad again, would you say he was one of the happier ones about his chosen field or about his life?

Halban: Yes. Yes, but with this huge proviso of everything that happened during the war. For somebody who, as I’ve said, was very competitive and who also, I think, sought recognition as part of his ambition. Not, I think, because he wanted to be famous and not, as I’ve already mentioned, because I think he wanted to derive personal financial benefit from his work. But I think just as a form of satisfaction and recognition, you know, “I did this. Surely it’s my right for everybody to acknowledge that I’ve done it.” I think that’s perfectly understandable in a scientist.

He didn’t, as far as I can see, aside from trying to defend the patents for the French government—and that was clearly done in the interest of the French, not as an individual scientist—I see no evidence for his having trumpeted his own success. I don’t think he was trying to overdo it; I think he just wanted some sort of fully justifiable recognition. The circumstances that we all understand now during the war, political and scientific, meant that in the end he probably wasn’t as well recognized as he and many others with hindsight thought he should have been.

Did that upset him or frustrate him? This is speculation, but probably yes. Did this make him embittered or unhappy? I don’t think so. I think he was—albeit demanding of those around him, whether colleagues or in the family—a fundamentally happy man. Certainly, towards the end of his career, committed to developing the lab and the reactor at Saclay, and very excited about that. I think on the whole, he came out okay. He would surely have come out better without the war. That’s true of so many people.

Kelly:  I was struck in reading his diary. He talked about someone whose name I’ve forgotten, but who had a breakdown. This was hugely tense and difficult times for so many people, including the scientists in his group at Cambridge.

Halban: That’s absolutely right. The pressure was enormous, because it was competitive, in any case, an innately competitive field at the cutting edge of contemporary science at the time. And because of the huge implications for the war effort. I have a very hard time imagining what it must have been like. I’ve worked in a competitive field, but without all the [1:34:43] fuss and stuff and nonsense that was going around at that time in terms of secrecy, pressure to get there first, pressure to get there before the Germans.

Pretty soon—and before the end of the war—pressure not to give anything to the Soviets. Gosh, I mean, just imagine what working under that sort of pressure, leaving aside the normal pressure of working in a competitive scientific field. I can imagine that some people couldn’t take it. I can also imagine that it led to people reacting in pretty extreme ways. Losing their patience, and maybe not doing things exactly as they would’ve done had there not been that sort of pressure. That’s what makes the history of this particular field so fascinating.

I’m in total admiration of you for taking on this whole project of preserving the atomic heritage, not only of your country, but, obviously, of the international effort. Now at this particular moment in your focus on this period of international research on the French effort, so thank you for your interest. It’s really important for the history of science, but also for obvious societal implications and interest as well.

Atomic Heritage Foundation