In Memoriam

Klaus Irgmaier Met His Death in a Tragic Accident

July 19, 2013 (PO19). On June 28, 2013, we lost our colleague and friend Klaus Irgmaier in a tragic accident at his home.

Klaus was born on December 23, 1966, in Munich. After graduating from school he studied physics at the Technical University of Munich where he graduated in 1996. During his PhD thesis, he designed and established test rigs for measuring the microwave surface impedance of HTS films with spatial resolution and characterizing the high frequency properties of HTS coatings as a function of composition.

In 2000 he joined THEVA and was responsible for the quality assessment of films and later for the entire infrastructure of the company, including IT, safety, and the production plant.

May 28, 2013 (PO18).  We regret to report that Dr. Joseph (Joe) LeConte Smith Jr., the Samuel C. Collins Professor Emeritus of Mechanical Engineering at Massachusetts Institute of Technology MIT) and retired Director of the MIT Cryogenic Engineering Laboratory, died on May 7, 2013, at the age of 83.

Born in Macon, Georgia on September 4, 1929, he attended Georgia Institute of Technology, receiving a BME degree in 1952, and an MS degree in 1953. He then served in the Signal Corps of the U.S. Army, before beginning his graduate work at MIT in thermodynamics and fluid mechanics. Starting as an instructor in MIT’s Department of Mechanical Engineering in 1956, he rose through the academic ranks to become Ford Professor of Engineering in 1991. In 1994, he was the first faculty member to hold the Samuel P. Collins Senior Faculty Chair, named after the founder of the MIT Cryogenic Engineering Laboratory, which Joe directed from 1964 until his retirement in 2008.

He was a consummate mechanical engineer who made innovative contributions to both education and research. In 1967, he introduced an innovative approach to undergraduate education in thermodynamics that prevails to this day. In graduate thermodynamics, he brought the thermodynamics subject into the 21st century.

In collaboration with Ernest Cravalho, he developed the textbook Engineering Thermodynamics. Joe was famous for his hands-on approach to engineering. He viewed the world as a problem in engineering design — so much so that when asked why any given natural phenomenon took the form found in nature, his standard reply was, “Because that’s the way I would build it.”

Smith’s research spanned fundamental areas of thermodynamics, heat transfer, electromagnetics, and cryogenics, and he was able to integrate these diverse fields to advance the practice of engineering. His success in this process was perhaps best manifested in his work with Gerald Wilson, on the development of the superconducting generator.  Stimulated by the first exploratory study by Woodson, Stekly et al., Smith and Wilson successfully demonstrated in 1968 a small vertical shaft alternator with a superconducting field winding and room-temperature armature.  The publication of this milestone work lead to multiple industrial efforts, which continue successfully until today, now with high-T_c windings.  In recognition of Joe’s many contributions to the practice of mechanical engineering, he was elected as a member of the National Academy of Engineering.  Among his other awards, he was also the Franklin Institute Laureate in Engineering (1987).

He served as a technical consultant to various corporations as well as start-up ventures. He also held many patents. After retirement in 2008, he continued to contribute his time to MIT and its cryogenic lab.  In addition to being an accomplished academic, he was also a skilled mechanic and carpenter. He will be remembered for always eagerly volunteering his knowledge and expertise.  At a recent symposium in his honor at MIT, many former students spoke of his influence on their careers.
 

Note: Cold Facts, the Newsletter of the Cryogenic Society of America (CSA) features tributes to Dr. Smith in their Summer 2013 issue.  Please click here to read these tributes.

Sergey Egorov Lost his Battle with Cancer
July 22, 2013 (PO20). Sergey Egorov passed away on March 24, 2013, after a one-year long battle with cancer. He was born on March 1, 1948 in Leningrad, USSR, which remained his hometown until end. Studies at the Leningrad Polytechnical Institute (now Saint-Petersburg State Polytechnical University) provided an excellent basis for the future carrier and scientific growth of Sergey as one of the leaders of the applied superconductivity in Russia. At the same time the streets of Leningrad remember the rustling of tires when the cyclist Egorov rushed to victories in student bicycle races. This hobby developed the qualities of a fighter, which armed Sergey for all future projects.

Sergei Egorov graduated as electrophysics engineer, and his all carrier was linked with the D.V. Efremov Institute of Electrophysical Apparatus (NIIEFA). His start there in 1972 coincided with the beginning of the development of applied superconductivity at the Efremov Institute. His early activity contributed to the positive outcome of the design and manufacture of the combined solenoid КС-250 (1975) with the record 25 T magnetic field, the 1.2 m in diameter solenoid “Giperon” (1978, with the magnetic field of 6 T and stored energy of 24 MJ) and other superconducting devices.

Sergey received his PhD in 1984 and the degree of Doctor of Science in 2006, both from the Efremov Institute. Last thirty years his professional activity was focused on supporting analysis and R&D of different superconducting magnet systems, mostly for superconducting magnetic energy storage (SMES) and tokamak reactors. As a project leader or an expert Sergey Egorov took parts in many international projects including tasks for MIT (USA), BWXT (USA), Jefferson Lab (USA), GHMFL (France), Ansaldo (Italia), DESY (Germany) etc. Sergey was a participant of L-star detector (SSC, USA, 1991), INTOR and ITER projects. In the frame of the ITER activity he was well known as an expert on AC-loss and stability analysis of superconductors. The valuable achievements of his activity included:

• Development of the design concept of fast discharge 0.2 Hz pulse repetition rate epoxy impregnated SMES units. Up to now the pilot sample of these SMES is demonstrated in the Efremov Institute Museum.
• Cost/efficiency optimization technique for SMES of various configurations and purposes. As a successful application of this technique, the charging magnet (2006) with 12.5 MJ stored energy for the floating coil of the joint Columbia University/MIT Levitated Dipole Experiment (LDX) experiment could be mentioned.
• Development of the AC-loss and stability calculation techniques for the composite strands and superconductors including ITER scale cable-in-conduit conductor (CICC). The Russian Federation’s largest experimental stand for the test and investigation of superconducting strands, cables, CICC and different kind magnets is the evidence of Egorov success in this field.
• Development of semi-empirical techniques for CICC stability analysis, design of test specimens and generalization of the experimental data contributed to ample success in the manufacturing and test of the ITER Toroidal Field Conductor Insert (TFCI). During testing at JAEA (Japan) the TF CICC demonstrated the world record of the operation with 46 kA current in 13 T magnetic field without degradation of stability margins.

Egorov headed the Superconducting Magnet Systems Department of the Efremov Institute for many years. Thanks to him the laboratories of that Department provide a wide range of possibilities for scientific and engineering studies in the field of the low- and high-temperature superconductivity (LTS and HTS). The PF-1 coil of the ITER poloidal system, the LTs solenoid and dipoles for different application, various LTS and HTS SMESs, HT superconducting current limiters, high-voltage insulating units for the cryogenic application, related stability, mechanical and thermal computation techniques are the incomplete list of the department activities which started and progressed under Sergey’s control and supervision.< p/>

He was a very creative man. His colleagues appreciated his experience, deep and broad knowledge as well as friendship and sense for humor. He loved life… All his friends remember the parties where poetry was recited and songs sung or collective gathering of edible mushrooms in the woods, with a lot of fun and chatting. All that gave Sergey necessary relaxation and energy to start new and new projects.

Sergey Egorov was author or co-author of about 100 publications. In his last years he successfully combined research activity with teaching load. He was appointed Professor of Saint Petersburg State University of Aerospace Instrumentation and read several training courses on nanotechnology and technical superconductivity. A lot of students owe him the necessary basis to start their carriers of scientist or engineer.

Since 1997 Sergey was a member of the Board of International Advisory Editors of Cryogenics. His professional reviewing helped many authors to publish important scientific and engineering results

Sergey left behind a wife who supported him in the fight with the awful disease, and friends who will remember him and strive to finish projects that were Sergey’s lifeworks. Let his memory be eternal

Igor Rodin & colleagues, NIIEFA

Henry Blosser, 1928-2013

August 4, 2014 (PO34). Henry Blosser passed away in March of 2013 at the age of 85.

Henry received his bachelor’s degree, master's degree, and his PhD from the University of Virginia. From 1954 to 1958 he worked at the Oak Ridge National Laboratory. He served as founding director and co-director of the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) from 1958 until his retirement in 1989. He was also an adjunct professor in the Wayne State University Department of Radiation Oncology in Detroit. He was a Guggenheim Fellow in 1973-74. In 1994 the American Physical Society awarded him the Tom W. Bonner Award for his contributions to nuclear physics. In 1984 the Detroit News named him "Michiganian of the year."

Henry was an innovator who supervised the construction of two superconducting cyclotrons at NSCL beginning in 1978 and into the 1980’s. These cyclotrons are still accelerating heavy ions at MSU. He also built a superconducting medical cyclotron for neutron therapy for use in a Detroit-area hospital. This cyclotron was used to treat patients from 1992 until 2012. It was the only such facility in the United States.

Kiyoshi Tsukasa, 1959-2013

December 13, 2013 (PO24).  Dr. Kiyoshi Tsukasa, the Group Leader of Magnet Development Group and the Office Chief of Planning and Coordination at the National Institute for Materials Science (NIMS) in Tsukuba, Japan, passed away on January 25, 2013, at the age of 53. He left behind his wife and son.

Kiyoshi was born in Hiroshima, Japan. He received his B.S. in 1983, M.S. in 1985, and Ph.D. in nuclear engineering in 1988 all from the University of Tokyo. In 1988 he joined the National Research Institute for Metals (now NIMS) and started research activity in high-field magnet technologies. His first research achievement was the development of 20 T large bore superconducting magnet (1992) that was cooled with saturated superfluid helium.

He was also in charge of the hybrid magnets at Tsukuba Magnet Laboratory (TML) and succeeded in achieving a series of world records for the highest steady magnetic field; 36.5 T in 1995 and 37.3 T in 1999. He was promoted to Group Leader of TML in 2001 and Director of TML in 2006. His research areas had covered both the superconducting materials (metallic and oxide) and superconducting magnets. His group attained the highest magnetic field of any superconducting magnet by successful generation of 24.0 T using HTS/LTS magnet (2011).

Since the late 1990s, he devoted his efforts to the high-field superconducting NMR magnets. Successful fabrication and operation of a series of high-field NMR magnets: 920 MHz (2001), 930 MHz (2004) and 1.03 GHz (under development) will be always remembered as pioneer work. In addition to achievements in the generation of highest magnetic fields, other Kyoshi’s research achievements included the development of high magnetic-field gradient magnet to form protein crystals in quasi-microgravity environment (2004) and the development of a magnetic flux concentrator using bulk superconductor as a magnetic lens (2009).

He served Applied Superconductivity and Magnet Technology communities as a member of program committees of Applied Superconductivity Conference (ASC) and International Conference of Magnet Technology (MT), was a member of Management Committee of the International Superconductivity Symposium ISS), a member of Iseult/Inumac Magnet Advisory Committee, and a vice-chairman of nomination committee of Cryogenics and Superconductivity Society of Japan for best presentations.

(PO17U). Gordon Bryce Donaldson was born in Edinburgh, Scotland on August 10, 1941 and died in Glasgow on November 28, 2012 at the age of 71.

Gordon was an undergraduate student at Christ's College, Cambridge from 1959 to 1962, when he received his BA. He and Christine were married in 1962, shortly after his graduation. Subsequently, he was a research student at the Royal Society Mond Laboratory, Cambridge from 1962 to 1965, when he received his Ph.D.

Under the supervision of John Adkins, Gordon measured the energy gap in Zn-ZnO-Zn tunnel junctions and investigated the subgap quasiparticle resistance of Al-AlOx-Ag tunnel junctions as an ultralow temperature thermometer. Immediately after receiving his Ph.D., Gordon became a Lecturer in the Physics Department at the newly created Lancaster University. He spent 1974 1975 on sabbatical leave at the University of California, Berkeley where, together with Mark Ketchen, Wolf Goubau and John Clarke, he developed the first thin-film, planar gradiometer based on a dc SQUID (Superconducting QUantum Interference Device).

In 1975, Gordon retuned to Scotland as a Lecturer in the Department of Applied Physics at the University of Strathclyde, Glasgow. In 1985 he became Professor of Applied Physics, a position he occupied until his retirement in 2006. On his arrival in Glasgow Gordon quickly established a new research group to make SQUIDs for useful applications. From modest beginnings with two staff and one tiny laboratory, the group grew steadily until, at its peak, it had approaching thirty members, plus a host of collaborators worldwide.

He and colleagues at Glasgow University and the city's Southern General Hospital secured substantial funding from the Wellcome Trust to set up a new biomagnetism facility in 1988 on the hospital campus, using SQUID gradiometers made at Strathclyde for measurements on patients and volunteers. Studies over ten years included fetal, stereopsis and spinal and peripheral nerve measurements.

Another of his main research interests was the use of SQUIDs for non-destructive evaluation (NDE), targeted at defects in aluminum and carbon-fiber aircraft components. This started long before the discovery of high temperature superconductors (HTS), initially with wire-wound gradiometers and niobium SQUIDs, but soon progressed to miniature thin-film niobium integrated SQUID gradiometers, made in the dedicated facility at Strathclyde. This was followed by major programs to develop and demonstrate HTS gradiometers for NDE, supported by a pulsed laser deposition system developed in the Group to grow HTS films and bi-crystal junctions.

Notable advances included the development of semi-portable NDE systems for use on curved surfaces and the application of neural nets to the interpretation of defects in carbon fiber composites. Gordon was very active within the superconducting community. He organized the International Superconductivity Conference (ISEC) at the University of Strathclyde in 1991. He was Coordinator for the UK Committee on High-Transition Temperature Superconductivity.

In 1991 he founded the Cambridge Winter School in Superconductivity to train junior researchers from the UK and overseas. He was Chair of the Low Temperature Group of the Institute of Physics, London. He spent productive sabbatical leaves at the University of Virginia in 1982 and at CSIRO in Sydney in 1999. His many achievements were recognized by his election as a Fellow of the Royal Society of Edinburgh in 1991.

Gordon is survived by his wife, Christine, by his children, Ian and Anne, and by two grandchildren.

We are grateful to Ian and Anne Donaldson for their help in preparing this remembrance.

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)