In Memoriam

Michael Wulf Belatedly Remembered

July 7, 2014 (PO33). Michael Wulf was born on May 9, 1978 in Hamburg and died unexpectedly at 34, presumably on November 16, 2012.

He studied physics at the Hamburg University, Germany (1997-2000), the Georgia Institute of Technology, Atlanta, GA, USA, (2000-2001) and University of Rochester, NY, USA, where in 2002 he earned his M.A. Subsequently, he worked there until 2006 towards a Ph.D.in the field of qubits and quantum computing control circuitry (RSFQ) utilizing superconducting devices. In particular, together with colleagues from Rochester, he published a very interesting paper about possible application of underdamped Josephson junctions in RSFQ comparators for the Josephson qubit readout (IEEE Trans. Appl. Supercond. 13, 974, 2003). His Ph.D. dissertation was planned that time to be on the subject of Steps Towards Superconducting Quantum Computing utilizing superconducting electronics.

In 2006 he moved to PTB Braunschweig, Germany (the German National Metrology Institute), to work in the Quantum Electronics Department on adaptation of cryo-electronic devices for qubit manipulation. He was involved in several EU research projects on superconducting quantum computation. Parallel to this research, he was very much engaged in the study of single electron circuits for application to electrical standards, especially the error statistics in networks of such devices. Eventually, he conceived the brilliant error accounting concept for practical realization of the quantum standard of electric current based on single electron tunneling (Phys. Rev. B 87, 035312, 2013 – the paper appeared after his death). Practical realization of this idea became the main and quite ambitious goal of his scientific life and, suddenly, the new theme of his PhD work. His first attempts to make such experiment using all-metallic circuits (Al electron pumps integrated with Al single electron transistors operated as electrometers) were not as successful as expected. Consequently, to implement this idea, Michael moved in 2012 within PTB to the Semiconductors and Magnetism Department to work on GaAs single-electron pumps for the future quantum current standard. The experimental work within that group, supported by his colleagues from Quantum Electronics Department (they complemented the semiconductor circuits with Al single electron electrometers) relatively soon resulted in a successful practical implementation of the concept, with Michael as a posthumous co-author (Phys. Rev. Lett. 112, 226803, 2014). That work was in 2014 awarded the prestigious Helmholtz Prize. Unfortunately he hadn't lived long enough to share this prize with the other awardees.

Not much is known about Michael’s private life and hobbies, probably because science itself was his main hobby. Still, we remember that he was an avid cyclist and had multiple interests, ranging from classical music and literature to economics and politics. His friends and co-workers remember having with him many discussions on such subjects during the ongoing measurements. At the same time he disliked unavoidable bureaucracy and boring paperwork, today an inseparable supplement of every active scientist’s research. He was interested in people, treated others with interest, respect and in a friendly manner, sometime with fine humor, while not hesitating to express his convictions and put right questions at the right time, thus moving things forward.

Michael Wulf (or Mike, as he liked to be called by colleagues) will always be in our memory as a brilliant minded and technically very gifted person. It is tragic that sudden death extinguished justified hopes for his many significant accomplishments yet to come.

His PTB colleagues

Loss of Dr. William (Rob) McGrath in Fatal Car Accident
August 14, 2012 (PO16).  MCGRATH, Dr. William (Rob)(56), died August 8th in a car accident. Born in Oklahoma City to William R. McGrath and Royetta Robinson. Rob graduated from Massachusetts Institute of Technology with a Bachelor of Science in Physics and attended University of California, Berkeley obtaining a Ph.D in Physics.

He was a Project Manager/Senior Research Scientist/Principal Physicist at JPL Pasadena supervising the Submillimeter-Wave Superconductive Sensors Group. Awards include: Lew Allen Award for Excellence from JPL, three other Recognition Awards from JPL, sixteen NASA Achievement Awards including two NASA Space Act Awards, and NASA Recognition Award for Analysis of "High-Tc Hot Electron Superconductive Mixer for Terahertz Applications". He held six patents, over 180 publications and participated in the following professional organizations: IEEE, APS, Sigma Xi, and MIT Club of SoCal. He enjoyed scuba diving, biking, snow skiing, astronomy and wood-working. He is survived by his loving wife Lisa, of twenty-five years, daughter Kelly, sisters Kathy Prichard of Royse City, TX, and Royan McCleskey of Southlake, TX and extended family members.

Jens Müller Is Victim of Tragic Accident

August 10, 2012 (PO15). On July 24, 2012 we lost our colleague and friend Jens Müller in a tragic accident. He drowned in the waters of Atlantic Ocean while saving the life of his son.

In the superconductor community, Jens was well-known as CEO of the German companies Trithor and Zenergy Power, which marked just two stations in his professional life fully dedicated to superconductor technology.

Jens was born on December 11, 1979, and as a lucky coincidence, graduated from high school just in the aftermath of the discovery of high-temperature superconductors (HTS). He immediately became attracted to this field, and the long-range perspective of solving fundamental issues in electric power technology by implementation of HTS.

He thus studied physics at the Friedrich-Wilhelm University in Bonn, graduated with honors, and then, with a Siemens scholarship, received his PhD on compound materials for superconducting wires and cables. He started his professional career working as an analyst for Deutsche Bank evaluating projects and portfolio companies for IPOs. Eventually, he profited from the know-how in financing when founding the start-up company Trithor. It was the time when the first wave of superconductivity hype already subsided and many big companies were withdrawing from the field. Jens recognized that a dedicated superconductor company would be necessary to keep things moving on. With the double strategy to produce superconducting wire as well as HTS components and devices, Trithor teamed up with the machine maker Bültmann to develop the first HTS-based induction heater of billets. After the insolvency of Trithor he managed to attract new investors to continue this development under the label Zenergy Power. From 2006 on, Jens led and expanded the Zenergy group with new subsidiaries in the US and Australia.

The first commercial breakthrough came in 2008 when the billet heater was successfully commissioned as the world’s first industrial scale HTS installation in a German aluminum extrusion plant. The convincing concept and large energy savings of this product were immediately recognized and awarded a number of prestigious prizes – among them the Hermes Award (2008, see HE15), German Environmental Award (2009), the Innovation Award for Climate and Environment (2009), and the European Business Award for the Environment (2010).

At the same time, Jens initiated within the Zenergy group the development of large HTS generators and fault current limiters for electric power supply. The first hydro-generator has been successfully tested and will be soon installed in a German hydro-power plant.  Another premiere was the first live-grid HTS fault current limiter installation that protected Southern California in 2010 from a power outage due to a sudden current surge. Jens also pushed the development of lower- cost HTS coated conductors. Zenergy started developing a 2G manufacturing process based on ink-jet printing and an all-chemical solution approach.

In 2011, the board of directors decided to abandon the superconductivity activities at Zenergy. Jens was released from his position at the Zenergy Power group and could not prevent the insolvency of the German Zenergy Power branch. To continue the work on HTS components, he founded,  together with former fellow partners, the engineering consulting company ECO5 with focus on the development of HTS wind power generators.

Jens Müller was a visionary – always one step ahead, and a tireless promoter of the HTS cause. He initiated significant developments and increased public awareness of superconductor technology. His inventions are documented in numerous patents.

Jens was a friendly and cheerful person, who gave hold, strength, and confidence to his colleagues and fellow men. His successes were due to expertise, tireless efforts deep commitment, and the unique skill to convince and to inspire others with his ideas.

Jens lost his life at the age of only 42. With him we have lost a protagonist of superconductor technology, an excellent businessman, partner, and friend. He has left marks, and the gap caused by his death will be hard to close. Our grief and deep compassion is with his wife and three kids.

By Werner Prusseit  (ivSupra) and Ursula Kollenbach (formerly Zenergy Power)

Carl Henning of LLNL Passed Away

August 2, 2012 (PO13). Carl D. Henning, born on Feb, 28, 1939, passed away on June 13, 2012 at the Hospice of the East Bay, California. Carl was a mechanical engineer having received his BS from Ohio University and his PhD from the University of Michigan. He spent most of his career at the Lawrence Livermore National Laboratory (LLNL) where he held many senior management and technical leadership positions in research toward controlling nuclear fusion as an energy source. Carl designed the “baseball” superconducting magnet at LLNL, was responsible for building the world's largest magnet at that time, but also designing massive containment vessels for stemming the oil fires in Kuwait. He spent two years on assignment in Germany as a member of the US contingent of scientists designing the International Thermonuclear Experimental Reactor, ITER.  Much earlier, Carl spent three years at Intermagnetics General Corporation IGC) as VP for Technology Development where he contributed to the development of an MRI machine for General Electric (see RN22).  In 1976-1978 he worked at the Dept. of Energy as Branch Chief in the Office of Magnetic Fusion.  He was Chairman of the ASC in the late 1980s.

Carl was the author of many technical papers and presentations, held five U.S. patents, and received numerous honors and awards, including being elected as a Fellow of the American Nuclear Society. In 2011 he was elected to the Fairview High School Hall of Fame in Cleveland, Ohio, where he was raised. Carl was an adventurer, rebuilding and flying his own airplanes, and in retirement, sailing a large catamaran which he and his wife, Judy, lived on in the Caribbean for several months of each year.  Among his numerous exploit, in 1988 he flew solo across the Atlantic Ocean in his Cessna 337 which he had rebuilt. Carl, with his infectious laughter, will be remembered by his many friends as a confident, self-sufficient man who relished daunting challenges.

Akira Tonomura Passed Away at 70

May 2, 2012 (PO8); updated May 7, 2012 (PO8-1). Akira Tonomura of Hitachi Central Research Laboratory died of pancreatic cancer early on May 2, 2012, at a hospital in Hidaka, Saitama Prefecture, Japan. He was 70. Tonomura was best known for developing electron holography for observing microscopic structures in matter using the wave nature of electrons and confirming the so-called Aharonov-Bohm (AB) effect, the existence of which had long been disputed among physicists. He was tipped as a future Nobel Prize winner for years. The sad news above we cite after the online Kyodo News of May 2, 2012.

Tonomura was born on April 25th, 1942. He graduated from Tokyo University (1965) and obtained his two doctoral degrees from Nagoya (Engineering, 1975) and Gakushuin (Philosophy/Physics) Universities. Joined Hitachi in 1965 and performed part of his doctoral research at Tübingen University, Germany (1973-1974 under G. Möllenstedt). In 1999 he became Fellow of Hitachi, the most prestigious level attainable there by a scientist. In 2001 he became also the Group Director of Single Quantum Dynamics Research Group at RIKEN. From 2003 to 2005 he served as President of Japanese Society of Microscopy.

After being for some years a visiting professor at Toyo University, TIT and Denki University, he became Professor of Toyo University (2008-2010). In 2011 was appointed Professor of Okinawa Institute of Science and Technology Graduate University.

Tonomura was Fellow of numerous societies of which we mention here the Japanese Society of Appl. Phys., APS (from 1999), the Microscopy Society of America, Eur. Phys. Soc., Institute of Physics (UK, 2007) and of AAAS (USA, 2007). Of his many honors and awards we list here the Nishina Memorial Prize (1982), Asahi Prize (1987), Japan Academy Prize and Imperial Prize (1991), and the Benjamin Franklin Medal in Physics (1999, USA). He became Member of Science Council of Japan (2005), Foreign Associate of Royal Swedish Academy of Engineering Science (2006), and Member of the Japan Academy in 2007.

Tonomura’s contributions to superconductivity started nearly a quarter of century ago when his group studied the AB effect and made the first single flux quantum observation by electron-holographic spectroscopy1. Subsequently, he and his group made real-time observations of vortex lattices in type II superconductors2 by Lorentz microscopy, and published multiple contribution on studies of such lattices and flux pinning in low- and high-Tc superconductors. The more complete overview of his numerous achievements in science can be found here.

¹T. Matsuda et al., Phys. Rev. Lett.62 2519 (1989).

²K. Harada et al., Nature, 360 (1992).

Siegfried Wolff 1939-2012

August 1, 2012 (PO12). Siegfried Wolff, a well known superconducting magnet expert, passed away after a long illness on March 13, 2012, at the age of 73. After his Physics Diploma in 1965 Wolff joined the bubble chamber group at DESY in Hamburg, Germany as a technical physicist. He made substantial contributions to the successful operation of the liquid hydrogen and deuterium bubble chamber and obtained his PhD in 1969 at the University of Hamburg with a thesis on bubble formation and growth in hydrogen and deuterium bubble chambers.

In the early 1970s, when the electron-positron storage ring DORIS was constructed, Siegfried Wolff moved over to magnet design and measurement. He designed the compensation coils for a DORIS experiment equipped with a superconducting solenoid, and under his leadership the magnetic measurements for the larger storage ring PETRA were carried out. When the proton-electron collider HERA was proposed, Siegfried Wolff joined the task force which was formed by Bjorn Wiik to design and construct the superconducting accelerator magnets of the proton ring. Wolff spent a sabbatical at Fermilab in 1979/1980 where he worked in the superconducting magnet group and acquired a thorough knowledge of the design principles and construction of the superconducting dipoles and quadrupoles for the Tevatron. Back at DESY he contributed heavily to the design of the HERA dipoles and quadrupoles, and in his group of engineers and technicians a number of protype dipoles were built that performed very well and exceeded the design field of 5 Tesla. In 1984 a radical design change was proposed to increase the field capability of the magnets and improve their quench safety. The warm-iron yoke of the Tevatron-like design was to be replaced by a cold-iron yoke directly surrounding the aluminium-collared coil. Within record time Wolff’s group built a short prototype of the new dipole which reached a field of 6 Tesla without training. The new magnet concept proved extremely successful in the industrially produced HERA magnets and had a strong impact on the design of the LHC magnets. During the construction phase of HERA, Wolff and his group performed the electric and cryogenic installation of the HERA proton ring.

When the HERA collider was completed, Wolff became head of the cryogenics group at DESY. He and his group contributed strongly to the successful R&D on superconducting cavities with accelerating fields above 25 MV/m, which was carried out by the international TESLA collaboration. Wolff’s group was also involved in the cryostat construction and provided the cryogenics for the TESLA Test Facility linac which was later upgraded to the free-electron laser FLASH.

Siegfried Wolff was a superconducting magnet expert of international reputation. He was a member of various advisory committees, among them the LHC Machine Advisory Committee, and he was co-author of a book on superconducting accelerator magnets. Siegfried Wolff will be remembered by his friends and colleagues for his great technical competence, his fairness and reliability, and his willingness to accept responsibility for demanding projects.

(By friends and colleagues at DESY)

Milan Polák Passed Away at 74

February 2, 2012 (PO7). Slovak scientist, Dr. Milan Polák, passed away on January 31st, 2012, after a severe short illness. His rather sudden departure at 74 came as a sad surprise to his colleagues and co-workers in Slovakia and abroad. He has been well-known to the superconductivity community through his active studies of electromagnetic properties of superconductors, superconducting magnets and devices, in particular on AC losses and related problems.

Milan Polák was born in 1937 in Strekov, finished university studies in 1960, got his Ph.D. in 1967 and the habilitation (D.Sc.) in 1989, both at Slovak Academy of Science (SAS) in Bratislava. From 1967 to 1969 he was in Giessen and Karlsruhe as Alexander von Humboldt Scholar, 1983 – 84 as lecturer at the L´Úniversité National de Gabés in Tunis and 1992–95 as visiting scientist in the Applied Superconductivity Center, Madison. Since 1960 he is with the Institute of Electrical Engineering (IEE), Slovak Academy of Sciences in Bratislava, Slovakia.

Polák made significant contributions to applied superconductivity, e.g., designed and tested NbTi coils for the generation of magnetic fields at industrial frequencies, AC loss measurements of superconductors and superconducting coils, development of low AC loss YBCO superconductors. He successfully managed several national and international research projects and published about 190 publications in international journals.

For 50 years he was active in the Institute Electrical Engineering of SAS and, to the end of his activity, liked the “hands on” experimental work in laboratory, which was a stimulating example also for much younger colleagues. He was also as a member of several scientific boards and, as the director of IEE, was also involved in effective reorganization of the Institute of Electrical Engineering at the time of “political change”.

Milan was a very creative colleague, and up to the end of his live stimulated others to useful activities.  His colleagues and collaborators appreciated his experience and knowledge as well as his friendship and sense for humour. For this author it was a special privilege to spend with him the time of his last MT-22 conference (Sept. 2011) and also participate in experiments performed together during his last years.

P. Kováč
IEE SAS

Marty Lubell of ORNL Died in Early 2012

August 1, 2012 (PO11). Another loss to superconducting community came only now to our attention.

Martin S. (Marty) Lubell, age 79, of Oak Ridge, passed away Monday, Jan. 16, 2012, at his home in Oak Ridge. Marty was born June 5, 1932, in New York City, N.Y., graduated from MIT and got his doctorate from the University of California at Berkeley. He initially worked at the Westinghouse Research Laboratories under Clarence Zener, but in 1959 moved from Pittsburgh, PA to Oak Ridge, TN, and worked as a physicist at ORNL and Y-12 until his retirement.

Marty was the Chairman of the 1982 ASC held in Knoxville. Among other his activities, he led the Oak Ridge superconducting magnet group that put together and tested the Large Coil Task (LCT) superconducting tokamak test solenoid of the early 1980s. Each of the “D” coils of that solenoid was constructed by a different commercial company or laboratory in order to get world wide experience in the construction of these devices. Marty was publishing on the LCF test results, see RN26.

Marty was a member of the Jewish Congregation of Oak Ridge, the Knoxville Museum of Art, and the United States Chess Federation; he wrote one of the 100 Greatest Chess Problems and was the Tri-State Chess Champion when he lived in Pittsburgh. He enjoyed refereeing soccer for both the AYSO (American Youth Soccer Association) and competitive leagues, skiing and the arts.

Antonio Barone Dies on December 4, 2011

December 10, 2011 (PO6). Antonio Barone (AB) prematurely passed away on Dec 4th 2011 at the age of 72, after a one-year battle with cancer. He left behind his wife Sveva and his two sons, Alberto and Livio. Antonio was currently Professor Emeritus at the University of Napoli Federico II, where he had been teaching for about 40 years.

The initial research activity of AB was in the field of nuclear physics. In this context, almost 45 years ago, the Ge “Lithium drift” semiconductor detectors represented a novelty, due to the high energy resolution allowed by those devices. Superconductors stimulated new approaches to radiation detection and this motivated Antonio’s interests toward superconductivity.

In the 1967 the birth of the Laboratorio di Cibernetica of the CNR offered him the possibility to work in a joint project USA-Italy (University of Wisconsin, Madison - CNR Naples) in the field of superconductivity on the peculiar subject of the superconductive “Neuristors”. His research activity on Josephson junctions opened a wide variety of very stimulating subjects in which AB was deeply involved, ranging from the soliton propagation in “long” Josephson structures to fluctuations phenomena, from light-sensitive junctions and proximity effect to the development of innovative superconducting devices.

The strong interaction of AB with the Landau Institute for Theoretical Physics of the Academy of Sciences, in Moscow, characterizes a long period of his research activity with a precious merging of theoretical and experimental aspects. All this body of work converged into the famous monograph on the “Physics and Applications of the Josephson Effect”, written in collaboration with Gianfranco Paternò in 1982. This became rapidly the reference text for the Josephson effect, as documented by thousands of citations and the fact it was translated into Russian, Japanese and Chinese. In 1983, AB was awarded by the Academy of Sciences in Moscow the highest academic title of “Doctor of the Physical-Mathematical Sciences”, and later the coveted Kapitza Prize.

The discovery of high-Tc superconductors (HTS) opened new problems and perspectives. In this context, AB and his group, significantly contributed by reporting original results on the “archetype” high-Tc Josephson junctions. Of great impact were the studies on unconventional superconductivity, first developed for ”p-wave” superconductors, but definitely very inspiring for the d-wave experiments on HTS compounds, and later on the physics of HTS Josephson junctions.

Macroscopic quantum phenomena and “particle detectors” are the keywords and the logical paths where to bring back several relevant contributions of Antonio scattered in more than 40 years of activity. Topics of his interest ranged from the fundamentals of macroscopic quantum tunnelling to barrier penetration in nonstationary fields, to finally a project into a wider vision of macroscopic quantum phenomena in unconventional systems.

Antonio is universally considered not only the founder of the Superconductivity School in the Napoli area, but also as the “grande maestro” and one of the most representative physicists in Italy. He has filled very relevant positions of scientific management in Italy and participated in many international committees. He has significantly contributed to the popularization of superconductivity as a divulgator, as a professor, as a researcher and as a manager.

An intense wave of sympathy and friendships has arrived from all over the world testifying how his gentleness, his sense of science and his smile were a solid bridge of friendship and respect with colleagues, students and people of everyday life. This premature departure cannot be dissociated from so many years spent working together. This moment cannot be dissociated from the awareness of having had the privilege to deal with a real gentleman of science and life, a man of vision and perspective.

Francesco Tafuri, Giampiero Pepe and Ruggero Vaglio.

Shoji Tanaka of ISTEC Died Suddenly at 84

November 14, 2011. Professor Shoji Tanaka, the preeminent luminary of Japanese superconductivity community suddenly died of pneumonia on November 11, 2011, at the age of 84. The Funeral ceremony was held on November 15th.

The IEEE Council on Superconductivity and European Society for Applied Superconductivity express their sincere condolences to ISTEC and all Japanese colleagues.

Shoji Tanaka was born on September 17, 1927. He obtained his B.S. in Applied Mathematics (1950) and Ph.D. in Engineering (1961) from the University of Tokyo. In 1999 he became honorary D.Sc. degree from the Purdue University, USA. In 1955 he was appointed Lecturer, in 1958 Associate Professor and in 1968 full Professor of the University of Tokyo. Upon his retirement in 1988 he was appointed Professor at the Department of Physics, Tokai University. He was also Consultant Professor of the Shanghai University, China.

Professor Tanaka was best known worldwide for his group’s confirmation of high-temperature superconductivity in cuprate oxides (1986) and the leadership of the International Superconductivity Technology Center (ISTEC). In 1988, he was appointed the first Director General of ISTEC’s Superconductivity Research Laboratory (SRL), which he directed until 2008. In 1988 he also became the Vice President of ISTEC. Currently, he was still Advisor to ISTEC/SRL. In his role, he wielded significant influence in the Japanese science community. We include the last unofficial photograph of him, a snapshot taken on October 24th at the ISS 2011 conference (24th International Symposium on Superconductivity, held at Tower Hall Funabori, Tokyo, October 24 to 26th), not much over two weeks before his passing away.

Shoji Tanaka was author or co-author of about 500 publications, of these over hundred preceding his first involvement with oxide superconductivity (in BaPb1-xBixO3 system) around 1984. His earlier interests concentrated among others on magnetoresistance and galvanomagnetic effects in semiconductors, for example doped Si, CdS, etc. He was also active in various semiconductor device structures, electron transport phenomena, and charge density wave effects in two-dimensional materials. He contributed to ESNF by his reminiscences “The History of ISTEC” (RN18, April 2011).

Professor Tanaka was decorated by the Emperor of Japan with the Purple Ribbon Medal in 1990 and with the 3rd Class Order of Merit of the Rising Sun in 1999. He also received numerous prizes: the Technical Achievement Prize of the World Congress on Superconductors in 1988, and the Greatest Prize of the Japan Ceramics Association, also in 1988. In 2003, the Japan Society of Applied Physics presented to Prof. Tanaka the Outstanding Achievement Award, and in 2004 the IEEE Council on Superconductivity presented to him the IEEE Max Swerdlow Award for Sustained Service to the Applied Superconductivity Community.

We make accessible the official ISTEC obituary received on November 15th.

Clyde Taylor of LLNL and LBNL Passed Away

August 1, 2012 (PO10).  Only now we learned that Clyde Taylor passed away November 16, 2011.  We publish this obituary based on the LBNL remembrance released by the LBNL News Center.

Clyde Taylor, a pioneer of superconducting magnet technology at both Lawrence Livermore and Lawrence Berkeley National Laboratories (LLNL and LBNL), died suddenly on November 16, 2011 at the age of 80.

Clyde was born December 5, 1930, in Susanville, CA, and attended Stanford University, where he majored in engineering.  He received his B.S. in 1952 and M.S. in mechanical engineering in 1953.  He then moved to Ventura and became Chief Drilling Engineer for Shell Oil Company’s West Coast Operations.

In 1956 Clyde began his work in superconducting magnets at Lawrence Livermore Lab, rising to become assistant director of the Lab’s magnetic confinement fusion program. He was active in Livermore community affairs and served on planning commissions and the city council, before being elected mayor of Livermore.

Livermore Lab’s fusion program at the time focused on mirror machines, in which plasma was confined by increasing gradients along magnetic field lines. Such machines required superconducting materials that could remain stable at very low temperatures while carrying very high currents and generating high magnetic fields. Livermore’s Jon Zbasnik recalls that, as part of the effort to build the Fusion Engineering Research Facility, and later the Mirror Fusion Test Facility – for which Clyde developed the “yin-yang” magnet configuration – he initiated research on niobium-tin, which is still at the  leading edge of superconducting magnet technology.

Clyde left Livermore in 1981 to join Berkeley Lab as head of the Supercon Group in the Accelerator and Fusion Research Division (AFRD), often working closely with Shlomo Caspi of Berkeley Lab’s Engineering Division. Clyde became head of the multilab engineering team that won the magnet design competition for the Superconducting Super Collider (SSC), whose planning efforts were based at Berkeley Lab. The SSC was canceled in 1993, but Caspi recalls that Clyde’s engineering skills and talent for management had led DOE to recognize AFRD’s strong position and unique analytical skills in the superconducting magnet field.

Clyde renewed his interest in niobium-tin as essential for advanced magnets when he led AFRD research toward achieving extraordinarily strong magnetic fields, beyond 10 tesla; he designed the first magnet to use windings of the material, according to Ron Scanlan, who in 1994 traded roles with Clyde and became supervisor of AFRD’s magnet group. The niobium-tin magnet they built achieved 13.6T in 1997, still a record. Today, similar magnets play an important role in AFRD’s designs for the planned Large Hadron Collider upgrade. During those years Clyde also put in place a special cabling machine at AFRD, which served as a prototype for industry and continues to supply cable to several DOE labs today.

At this time, as Scanlan recalls, Clyde also developed a solution to a major problem limiting the performance of accelerator magnets: the movement of structural elements under the tremendous forces generated by the magnets themselves, which can lead to disastrous “quenches.” His solution was a system of keys and bladders filled with liquid metal to prestress critical components. Refined by Shlomo Caspi, the bladder and key design made possible a series of record-breaking superconducting magnets built at Berkeley Lab.

Beginning in 1995, Clyde developed the “superbend” insertion devices that allowed the Advanced Light Source, built to optimize soft x-ray production, to extend operations well into the hard x-ray region, a requirement for protein-crystallography beamlines that are among the ALS’s most productive, according to AFRD’s Alan Jackson. Developed in cooperation with an industrial firm, Wang NMR, the Superbends are unique to the ALS among the world’s synchrotron light sources, which now has several of them.

Also in 1995, Clyde applied the bladder and key concept to his design for the superconducting magnet structure of a new kind of ion source for the 88-Inch Cyclotron, proposed by Claude Lyneis of the LBNL Nuclear Science Division. Called VENUS (”versatile ECR ion source for nuclear science”), the new source would be capable of producing high currents of ions, from hydrogen all the way to uranium, but required the highest magnetic fields ever achieved in this kind of ion source. Lyneis notes that the outstanding performance of VENUS, completed in 2003, was a key factor in enabling the rare ion beam facility now under construction at Michigan State University.

Clyde continued to work on both the Superbends and VENUS after his 1996 retirement and subsequent rehire as a consultant, continuing part time at the Lab until 2008. His lifelong enthusiasm for long-distance bicycle trips, backpacking, and cross-country skiing continued, as did his passion for travel abroad and for theater.

Clyde is warmly remembered by his many associates over the years as “a true gentleman” (Alan Jackson); “a very sincere, very kind, and very warm person, with great devotion to his work” (Bert Wang); “my mentor, supervisor, and friend for over 25 years, and one of the best people I have known” (Ron Scanlan); “a gentle person, soft-spoken and a great traveling companion [who] liked people and was eager to help, especially young people at the beginning of their career” (Shlomo Caspi); and many others, including Claude Lyneis, who put together the LBNL remembrance.

Per Dahl Succumbed to Cancer

May 16, 2012 (PO9). Belatedly, we learned that Per Dahl passed away in 2011. Below we reproduce in full the obituary submitted by Peter Wanderer of Brookhaven National Laboratory.

Per Fridtjof Dahl, a physicist expert in superconducting accelerator magnets, artist, and historian of modern physics died on October 1, 2011 after a two-to-three year-long struggle with lung cancer.

Per Dahl was born at Georgetown Hospital in Washington, D.C., on August 1, 1932. His parents were Odd Dahl, from Drammen, Norway, and Anna Augusta (Vesse), from Eau Claire, Wisconsin. Dahl was born while his father was working at the Carnegie Institution in Washington, D.C. In 1936, his father saw the war coming and decided to take his family back to Bergen, Norway. He returned to Norway in 1937 to oversee science in Norway during the war.

Dahl grew up in Bergen, Norway, from the age of 4 until he was 17. He then came to the U.S. and served three years in the U.S. Army, including two years stationed on Guam in the Pacific. Taking after his father, Dahl was interested in science and physics from an early age. He studied science during his Army years, and after leaving the service he entered the University of Wisconsin, obtaining his Ph.D. in Physics in 1960. His post-doctoral work was done at the Niels Bohr Institute in Copenhagen, Denmark.

Per Dahl joined the Brookhaven National Laboratory (BNL) in 1963. He arrived at a time when superconductors were beginning to move from laboratory development to industrial production. At this time, development of accelerator magnets using NbTi and Nb₃Sn began. Per became involved in the design of these magnets early in his BNL career and acquired a good understanding both of the materials and their use in magnets. He put this knowledge to good use later in his BNL career when he became the principal person writing about magnets and superconductors for technically-oriented audiences. This work also provided him with an opportunity to display his skills as an artist. His drawing that shows all the critical components of a superconducting cable is still used in talks for visitors to Brookhaven.

Per began working on the larger stage of the Superconducting Super Collider (SSC) in 1987, where he continued work documenting the magnet program. When the SSC effort moved from the design location, Berkeley, to the laboratory location in Texas, Per expanded his work to include both the documentation of the conventional construction effort and preparation of information in support of the SSC mission (e.g., publisher of the SSC News). Following termination of the SSC project in 1993, Per moved to the Accelerator and Fusion Research Division at Lawrence Berkeley National Lab (LBNL).

During much of that time he was on leave to the Office of High Energy Physics, where he was Program Officer for a number of university grants. He also consulted with BNL about the nascent RHIC magnet system. He retired from LBNL in 1996 but kept contact with the lab through a visiting scientist appointment and work at the Office for the History of Science and Technology at UC-Berkeley until 2005.

Dahl is the author of numerous scientific papers and several books: From Nuclear Transmutation to Nuclear Fission, 1932-1939 (Institute of Physics Publishing, Co., Bristol, England and Philadelphia, PA, USA, 2002); Heavy Water and the Wartime Race for Nuclear Energy (Institute of Physics Publishing, Co., UK, Bristol England and Philadelphia, PA, USA, 1999), which was featured in the NOVA TV-production, Hitler’s Sunken Secret, DOX Production, London, 2004; Flash of the Cathode Rays: A History of J.J. Thomson’s Electron (Institute of Physics Publishing, Co., UK, Bristol, England and Philadelphia, USA, 1997); Superconductivity: Its Historical Roots and Development from Mercury to the Ceramic Oxides (American Institute of Physics, New York, 1992); Ludvig Colding and the Conservation of Energy Principle: Experimental and Philosophical Contributions, The Sources of Science N. 104 (Johnson Reprint Corp., New York and London, 1972).

Throughout his life, Dahl was able to pursue his love for physics, art and his family. While at Brookhaven, he was a president of the South Bay Art Association (1967-1968), and he was also the president of the Brookhaven National Laboratory Art Society for several years. He was a fellow of the American Physical Society.

He is survived by his devoted wife of 45 years, Eleanor, and two sons: Erik (married to Christa), of Pebble Beach, CA; and Thomas (married to Jo) and two grandchildren, Emily and Alex, of Westford, MA.

Peter Wanderer, Brookhaven National Laboratory, NY
Eleanor Dahl, Emeryville, CA
Erik J. Dahl, Pebble Beach, CA and Thomas F. Dahl, Westford, MA