Awardee Interviews | Biography: Dr. Hajime Ishimaru
Dr. Hajime Ishimaru
Hajime Ishimaru was born in 1940 in Sapporo, Japan and graduated high school in Sapporo. He received a B.S. degree in physics from Hokkaido University in 1963 and an M.S. in nuclear physics from Tohoku University in 1965. In 1970, he received the SciDr in plasma physics from Nagoya University where his research was in energy-mass analysis for highly ionized steady state plasma. Dr. Ishimaru received the Eng.Dr. from Tokyo University in 1980, working in the areas of vacuum feedthroughs-coaxial, multi-pin/coaxial multi-pin complex vacuum feedthroughs in ultrahigh vacuum and cryogenic.
From 1969 to 1972, he worked at the Tokyo University as Research Associate on diagnosis of the plasma and molecular beam. In 1972, Dr. Ishimaru joined the National Laboratory for High Energy Physics in Tsukuba, Japan. He currently heads the TRISTAN Vacuum Group, an aluminum constructed electron-positron collider beam storage ring and the B Factory under construction. He directed the construction of the beam transport line of the proton linear accelerator, beam monitoring and operation of the proton synchrotron, development of the all aluminum alloy vacuum system, and construction of TRISTAN e+e- large storage accelerator. As Professor, he also manages the research of Ph.D. Graduate students for Accelerator Science, The Graduate University for Advanced Studies in Japan.,
A major contribution of Dr. Ishimaru was in aluminum vacuum technology where he pioneered the development of all aluminum ultrahigh vacuum materials, components, and systems for vacuum in the low 10-23 Torr region. In 1977, he discovered the residual radioactivity in aluminum decays with half-life as short as 15 hours and the first to have experimental data on the decay of the residual radioactivity of vacuum material. He then embarked upon developing techniques for surface treatment of aluminum. Initially, EX-mirrored finished was developed by enclosing the working portion of a lathe in a larger vacuum chamber under a controlled atmosphere of oxygen and argon gases. A diamond tipped tool was used to cut the inner surface of high purity aluminum producing a new oxide layer of less than 3nm thick. Other surface treatments developed were EX-extrusion, EX-process, and EX-GBB process. Outgassing rates for these surface treatments after a 24 hour bakeout at 150o C was in the low 10-14 Torr L/s cm2. Dr. Ishimaru developed special welding techniques for aluminum by TIG for flanges, fittings, vacuum vessels, and electron beam welding for feedthroughs and bellows for very small weld seams.
To complete this new aluminum technology, Ishimaru has developed an all aluminum conflat flange, titanium carbide coated knife-edge together with a re-usable aluminum gaskets and high strength aluminum nuts and bolts. He developed an aluminum single structure bellows for connecting to the beam line chamber for baking and adsorption of mechanical distortions and for the tolerance against "meltdown" by the particle beam. Other developments included aluminum metal seal right angle valves, double metal-seal gate valves, optical windows, feedthroughs, manipulators, non-water cooling vacuum furnace, and a portable vacuum suitcase using very light weight aluminum alloy honeycombed panels. Also, a turbomolecular pumps was developed by cooling the rotor with ceramic coating to achieve vacuum in the low 10-12 Torr region. Sputter ion pumps and titanium sublimation pumps were also made from aluminum alloys. With the different aluminum components and pumps, an extremely high vacuum system of the order of 10-13 Torr was developed using an aluminum alloy quadrupole mass filter. A very fast pump-down system was also developed employing special moisture traps to acheive vacuum of 10-8 Torr region in less than 150 seconds.
Dr. Ishimaru is a Technical Consultant to Korea POSTECH 2 GeV synchrotron radiation source; DAϕNE Collider Project for INFN Frascati, Italy; Taiwan 1.5 GeV Synchtron; Spring-8, Japan; Space Shuttle's "WAKE" Project in collaboration with the Space Epitaxy Center in Houston University, and SSC Main ColIider Beam Tube/HEB (now terminated). He was also instrumental in the design and development of a 40 m L-shaped aluminum alloy chamber and vacuum tank with laser beam reflecting mirror system for the National Astronomical Institute in Japan.
His work has been very extensively cited by others in the high vacuum field. He has authored and co-authored over 185 papers in vacuum journals and conference proceedings and four technical book publications. Dr. Ishimaru has 40 registered patents and over 100 patents pending. He is a Member of AVS, Japan Society of Vacuum, the Japan Society of Applied Physics, Japan Institute of Light Metals, and Member of the Editorial Advisory Board for "VACUUM," a British Vacuum Journal.
Dr. Ishimaru received numerous awards and honors for his work. In 1978, he received the Award of Excellence, Best Shop Note by the American Vacuum Society for the first bakeable metal-seal aluminum alloy flange system. Since it was the first award, he was not able to attend the award ceremony in New York due to budget constraints. In 1979, the Vacuum Society of Japan awarded Dr. Ishimaru for his contribution in the development of an 14 pin/BNC coaxial combination for cryogenic vacuum and microwave performance in the Ghz region, and in 1982, for development of the first all aluminum alloy vacuum system. He received Japan's 42nd Remarkable Patent Award in 1983 for vacuum and cryogenic performance, high density, and quick connect and disconnect of the 14 pin/BNC coaxial combination feedthrough. In 1985, Japan's Remarkable Patent was awarded to Dr. Ishimaru for development of very thin and high performance thermal insulation with no particulates for vacuum systems. He received an award from the British Vacuum Society in 1985 for the first beryllium window mounted on aluminum by electron beam weld. In 1989, Physics News, from the American Institute of Physics, for the first practical 10-13 Torr XHV aluminum system and in 1991 the TAKAGI AWARD from the Institute of Japan for the first Ball Screw and Ball Bearing in UHV with long life time. Dr. Ishimaru received Taiwan's highest honor for technical contribution to vacuum technology to the SRRC Project at a dedication ceremony on October 1993, Hsinchu, Taiwan.
Dr. Ishimaru was instrumental in the establishment of ALVALAB (Aluminum Vacuum Laboratory) in 1988, an international private research consortium to develop and promote aluminum ultrahigh technology. Today, 63 member firms worldwide offer aluminum vacuum components and system technology. Dr. Ishimaru is known as the "Father" of ALVALAB.