Learning About Infinitesimally Small World of Elementary Particles Is The

The Japanese scientific community is In experimental physics, however, Professors Shuji Orito, Sakue Yamada, and producing many of the world’s leading experiments and observations are conduct- Yoji Totsuka. ed in order to better understand natural or I became a student of Professor Orito researchers in the field of elementary physical phenomena or to prove theories when I transferred from Waseda University particle physics developed in theoretical physics. One of to complete a master’s degree at the Physics can be roughly divided into Japan’s most renowned experimental phys- University of Tokyo. So, I am essentially two disciplines: theoretical physics and icists is Masatoshi Koshiba, who won the a second-generation pupil of Professor experimental physics. The former seeks 2002 Nobel Prize in Physics for his detec- Koshiba. to develop theories to explain known tion of neutrinos. I was only ever an average athlete empirical facts and natural phenomena Saeki: Professor Koshiba is a pioneer of during my childhood, but I loved to draw or to study unexplained physical phenom- Japanese experimental physics. Following and ponder things—that’s why I was ena based on mathematical hypotheses. his return to the University of Tokyo after sometimes called “child Buddha” [laughs]. Prominent Japanese scientists in this studying in the United States, the profes- I was good at science and math. At that discipline include Yoshio Nishina, Hideki sor led his own laboratory. The first three time, science was all the rage. Rather than Yukawa, and Shinichiro Tomonaga. researchers to join his laboratory were the class lectures and textbooks, though, I

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Profile of Associate Professor Takayuki Saeki Born in 1966 Mar. 1990 B.S. in physics, Department of Applied Physics, Faculty of Science and Engineering, Waseda University Apr. 1992 M.S. in physics, Department of Physics, Faculty of Science, University of Tokyo Sep. 1996 Ph.D., Department of Physics, Faculty of Science, University of Tokyo Sep. 1996 Research Associate, University of Tokyo, International Center for Particle Physics (ICEPP) Mar. 2004 Research Associate, Accelerator Laboratory, High Energy Accelerator Research Organization (KEK) Apr. 2008 Senior Assistant Professor, Accelerator Division VI, Accelerator Laboratory, High Energy Accelerator Research Organization (KEK) Apr. 2015-Present Associate Professor, Accelerator Division VI, Accelerator Laboratory, High Energy Accelerator Research Organization (KEK)

Associate Professor, Accelerator Laboratory, High Energy Accelerator Research Organization (KEK) (Inter-University Research Institute Corporation) Dr. Takayuki Saeki Learning About Infinitesimally Small World of Elementary Particles is the Springboard for Learning About the Vast Expanses of the Universe The International Linear Collider (ILC) is Expected to Unravel the Mysteries of Life and the Creation of the Universe

“Large accelerators are a fitting symbol for elementary particle physics. Without them, we would be unable to carry out experiments to explore the world of elementary particles, and without these experiments, we would be unable to make advancements in physics.” The above statement is a quote from a book published* by Dr. Yoichiro Nambu, who was awarded the Nobel Prize in Physics in 2008 along with Dr. Makoto Kobayashi and Dr. Toshihide Masukawa. Dr. Nambu goes on to say that in order to unravel the mysteries of the universe, “the amount of energy produced by accelerators must be increased if we are to discover new elementary particles and investigate unexplained interactions.” In other words, once studies have been conducted into all of the possible reactions that an accelerator can trigger, the accelerator no longer has a useful role to play. For any further studies, a new accelerator that can produce much greater energy is necessary. By leveraging the capabilities of researchers from all over the world, the High Energy Accelerator Research Organization (known as “KEK”) is leading an international project to build the new International Linear Collider (ILC). In this “Vison” section on the ILC, we discuss accelerators and elementary particles with Associate Professor Takayuki Saeki, who is at the forefront of the accelerator cavity technology that underpins the ILC. * Yoichiro Nambu, Quarks, Second Edition, 1998, Kodansha Bluebacks

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KEK’s History was more interested in spe- 1971 High Energy Physics Research Organization cialist science publications. I established (Apr.) 1976 Proton accelerator (PS) succeeded in accelerating studied them by myself and protons to 8 GeV (Mar.) daydreamed about the Big PS succeeded in accelerating protons to 12 GeV (Dec.) Bang. I had already decided 1982 Photon Factory (PF) succeeded in storing electron to become a researcher by beam energy of 2.5 GeV (Mar.) 1986 Tristan Main Ring (MR) accelerated both electron and going to university to study positron beams to 25.5 GeV (Nov.) applied physics. 1998 B-factory succeeded in storing beams (Dec.) As we now know, the World’s highest luminosity achieved, laying the stars that we see in the night groundwork for the Nobel-prize-winning theory by Dr. sky are actually hundreds Kobayashi and Dr. Masukawa. 2009 J-PARC constructed jointly with Japan Atomic Energy of thousands of light years Agency (Mar.) away, and what we see is Long baseline neutrino oscillation (T2K) experiment actually images of them as Aerial view of the entire KEK Tsukuba Campus commenced (Apr.) they were at a point in the (Source: KEK) 2016 Beams successfully stored by the SuperKEKB (Feb.) past as the light has to travel through the unimaginably vast universe produced many talented individuals who Kajita discovered evidence of neutrino before it reaches us. On hearing this, chil- are leading the world in the study of ele- oscillations based on the increased amount dren in kindergarten or primary school mentary particles with the aim of unveiling of observational data processed by “Super- tend to respond by asking: “But what’s the secrets of the universe. As a researcher, Kamiokande”, which has a capacity 15 beyond the stars?” Grownups—and even I too have benefited from the tutelage pro- times greater than that of “Kamiokande”. great teachers—are unable to answer that vided in this community. This discovery was recognized with a question. Given this, I decided that I would Nobel Prize. In this experiment, a high have to figure this out for myself. KEK’s accelerators have played intensity proton accelerator (J-PARC) While I was studying for my doc- a part in studies that have won operated by KEK was employed to artifi- torate from 1993 to 1995, I took part in a the Nobel Prize for Physics cially create and supply irradiate neutrino series of experiments in Canada where we beams to “Super Kamiokande”, which used a balloon-borne instrument to observe Elementary particles are the small- successfully observed the neutrino oscilla- cosmic radiation. For each experiment, the est component of a substance and they tions. balloon was sent at the altitude of about 30 cannot be broken down any further. What KEK’s accelerator helped prove the km into the air. After the observations had we consider to be elementary particles existence of quarks as new elementary been completed, the rope was cut between has changed over time. Much of today’s particles in line with the theories of Dr. the balloon and the instrument so that the research into elementary particles is con- Makoto Kobayashi and Dr. Toshihide observation instrument could be returned ducted in an effort to validate theoretic Masukawa. Together with Professor to the ground by means of a parachute. physicists’ theories through a comparison Yoichiro Nambu, these theoretical profes- Together with a retrieval team, the with the results of experiments conduct- sors won the Nobel Prize for Physics in other researchers and I would then search ed by experimental physicists. If such 2008. the forests and fields for the landing research leads to a breakthrough, it could As a Japanese center of development instrument. If we couldn’t use a car for set us on the path to a new scientific civili- for accelerator science, KEK provides the search, we would charter a military zation that is beyond conventional thinking. opportunities for both Japanese and inter- plane or trek by foot. My worst experi- Saeki: Research into the infinitesimal- national researchers in related fields to ence was when we had to search a marsh ly small world of elementary particles conduct research using its various accelera- for the instrument. I learned the hard way requires the use of special systems. tors. that the job of an experimental physicist Professor Koshiba, for example, studied It may surprise some people to learn can be very tough—it can be physically neutrinos by observing them with a system that applications of accelerator technolo- demanding and require great perseverance called “Kamiokande”, which is situated gies can be found in our everyday lives. [laughs]. The project leader back then was 1,000 m below the former Kamioka mine The microwave ovens found in most Professor Orito. in Gifu Prefecture, Japan. homes are based on the same principle as The Japanese physics community has Sometime later, Professor Takaaki that of the high-frequency electromagnetic

Figure 1: What is water made of? Elementary particles Force carriers Generation I Generation II Generation III All elements consist of Strong force Water molecule three types of elementary u c t g particles (electrons, up Charm Top Oxygen quarks, and down quarks). Up Gluon Quarks atom d s b Electromagnetism Drop of water Down Strange Bottom r Photon Hydrogen atom Weak force Neutron e neutrino μ neutrino τ neutrino ＋－ Up quark w w z Leptons e Electron Muon Tau W bosons Z boson Superconducting accelerator cavity unit An ideal vacuum is essential in accelerators. This photo Particles generated by the Higgs field H Nucleus Proton shows an ULVAC ion pump. Electron cloud Down quark Higgs boson (Illustration created based on materials provided by KEK) Figure 3: Elementary particles that shape the universe (Image courtesy of KEK) ｜ 15 Return pipe for helium gas Thermal insulation field generators used in accelerators. Many shield Supply pipe for liquid helium other examples exist, including PET scan- ners for cancer screening, electron micro- scopes, sterilization units, X-ray diagnostic equipment, radiation therapy equipment, non-destructive testing equipment, and even obsolete appliances such as tube tele- visions. The accelerator is an essential tool Superconducting for elementary particle physics researchers. acceleration cavity

Indispensable accelerators for elementary particle Figure 7: Cross section of cryomodule (Image courtesy of E-XFEL/DESY) physics research Figure 5: Cryomodule (Image courtesy of KEK (C) Rey. Hori) Supply pipe for liquid helium Cryomodules are used in the KEK accelerator unit with a diameter of 1 m The microscope is a well-known tool and a length of 12 m. Each module consists of a superconducting for observing the world of the infinitely accelerator cavity unit or a superconducting quadrupole magnet, and a vacuum insulation vessel to provide thermal insulation for the helium small. Theoretically speaking, though, it is Liquid helium vessel impossible for a microscope to observe the piping. Two types of cryomodules are used: one houses nine Turn-around (RTML) Positron accelerator superconducting acceleration cavity units, while the other houses eight Beam pipe molecular world at scale of 100 millionth superconducting acceleration cavity units and one superconducting of a centimeter—but an accelerator can. quadrupole magnet. In the ILC, 1,680 cryomodules are installed in a Saeki: The presence of electrons inside straight tunnel underground. Key beam parameters of the ILC Beam delivery atoms was known as early as the late 19th system Frequency tuner Electron gun Detectors: ILD & SiD century, and Ernest Rutherford attempted Beam energy 500GeV(250GeV+250GeV) Figure 6: Superconducting acceleration cavity unit to visualize the internal structure of an Luminosity 1.8 x 1034cm-2s-1 (Image courtesy of KEK (C) Rey. Hori) atom in 1911. To do this, he collided alpha A superconducting acceleration cavity unit is a system that integrates a 9-cell No. of particles / bunch 2.0 x 1010 particles rays from radioactive elements at atoms to cavity with an acceleration gradient of 31.5 MV/m, a helium jacket around the No. of bunches / pulse 1,312 Beam delivery cavity that can be filled with liquid helium, and a frequency tuning mechanism observe the degree of deflection or pene- system to maintain and control resonance in the cavity. A cavity made using niobium tration. His experiments revealed that some Pulse frequency 5Hz approx. 30 km Damping ring (Nb) becomes superconductive without electric resistance when it is cooled to negatively charged objects, which we now Acceleration gradient 31.5MV/m Positron source an absolute temperature of 2 K (or -271°C) using liquid helium. It can generate call electrons, were flying around some a high accelerating electric field with a small amount of RF power. Collision beam size 474nm x 5.9nm sort of a positively charged mass, which turned out to be the nucleus. Mr. Rutherford’s collision of alpha Electron accelerator rays at atoms marks the beginning of accelerators, and the principle has not changed since then. As a matter of fact, Figure 8: ILC detectors (Image courtesy of KEK (c) Rey. Hori) Turn around (RTML) accelerators are also referred to as collid- Figure 4: Schematic illustration of ILC (Image courtesy of KEK (C) Rey. Hori) A collision detector placed at an interaction point (IP) ers. As it turns out, such collisions must be between electron beams of 250 GeV and positron beams made by accelerating particles with much of 250 GeV captures the trajectory of particles involved higher energy in order to study the inside in each interaction. The plan for a collision detector of the atomic nucleus in detail. envisages the employment of ILD and SiD, and these two Initially, the atom was believed to detectors will be used alternately in experiments. be made up of electrons, protons, and neutrons. However, following the development of technologies for space observation of the entire universe. The mysterious dark gravitational forces. and experiments with accelerators, the matter and dark energy account for the Saeki: Electromagnetism, the most existence of minuscule particles—called remaining 23% and 73%, respectively. It familiar of the fundamental forces, can quarks—in protons and neutrons was pre- is believed that research into dark matter be observed with lightening and magnets. dicted in 1964. Their existence was proven and energy will help us to understand the This type of force is mediated by elemen- in 1969 in an experiment conducted in beginning and evolution of the universe, tary particles called photons and it acts America using an accelerator. so hopes for new accelerators are growing among electrically charged elementary In 1973, a theory proposed by Dr. (Figures 2 and 3). particles. Both weak and strong forces act Kobayashi and Dr. Masukawa predicted among protons and neutrons inside the the existence of six types of quarks, includ- Electromagnetic, strong, weak, atomic nucleus. The strong force is medi- ing up and down ones. As mentioned ear- and gravitational: the four ated among quarks to keep the protons lier, the theory was validated using a KEK fundamental forces mediated and neutrons inside the atomic nucleus. accelerator. Subsequently, new particles According to conventional thinking, pro- by elementary particles believed to be the root elements of matter tons inside the nucleus would repel one were discovered, such as the electron-like Elementary particles are believed another due to their positive charges, but lepton. Today, we can no longer declare to mediate the four fundamental forces this does not happen thanks to elementary with any certainty that we have a definite behind all interactions involving matter on particles called gluons, which bond protons conclusion. the Earth, in the solar system, in the uni- together with their strong force (Figure 3). In fact, it has been revealed that verse, and on any natural world that lies The weak force, which is carried by the particles forming hydrogen and other beyond. These four forces of interaction elementary particles called Z (W) bosons, familiar substances only account for 4% are the electromagnetic, strong, weak, and acts on quarks and leptons to trigger nucle-

16 ULVAC ｜ No.67 (October, 2017) Return pipe for helium gas Thermal insulation shield Supply pipe for liquid helium

Superconducting acceleration cavity

Figure 7: Cross section of cryomodule (Image courtesy of E-XFEL/DESY) Figure 5: Cryomodule (Image courtesy of KEK (C) Rey. Hori) Supply pipe for liquid helium Cryomodules are used in the KEK accelerator unit with a diameter of 1 m and a length of 12 m. Each module consists of a superconducting accelerator cavity unit or a superconducting quadrupole magnet, and a vacuum insulation vessel to provide thermal insulation for the helium piping. Two types of cryomodules are used: one houses nine Liquid helium vessel Turn-around (RTML) Positron accelerator superconducting acceleration cavity units, while the other houses eight Beam pipe superconducting acceleration cavity units and one superconducting quadrupole magnet. In the ILC, 1,680 cryomodules are installed in a straight tunnel underground. Beam delivery system Frequency tuner Electron gun Detectors: ILD & SiD Figure 6: Superconducting acceleration cavity unit (Image courtesy of KEK (C) Rey. Hori) A superconducting acceleration cavity unit is a system that integrates a 9-cell cavity with an acceleration gradient of 31.5 MV/m, a helium jacket around the Beam delivery cavity that can be filled with liquid helium, and a frequency tuning mechanism system approx. 30 km to maintain and control resonance in the cavity. A cavity made using niobium Damping ring (Nb) becomes superconductive without electric resistance when it is cooled to Positron source an absolute temperature of 2 K (or -271°C) using liquid helium. It can generate a high accelerating electric field with a small amount of RF power.

Electron accelerator

Turn around (RTML) Figure 4: Schematic illustration of ILC (Image courtesy of KEK (C) Rey. Hori)

ar decay. It is owing to this force that our Sun is able to continue burning. The gravitational force remains a complete mystery—nothing is known about it. This feebleFigure force of1: attractionWhat is water made of? Elementary particles Force carriers does not involve any positive and negative Generation I Generation II Generation III Strong force charges or any correspondingWater force of repulsion. It is so feeblemolecule that static elec- Hydrogen and other matter u c t g Charm Top tricity that has beenOxygen built up on a celluloid Up Gluon Quarks atom d s b Electromagnetism sheet can lift up our hair. This phenomenon Drop of water demonstrates that the force of attraction Dark energy Down Strange Bottom r exerted on hair by a celluloid sheet charged Photon with static electricity is stronger thanHydrogen the atom Weak force Neutron e neutrino μ neutrino τ neutrino ＋－ gravitational force exerted by the vast mass Up quark w w z Dark matter Leptons e of the earth. Tau W bosons Z boson In 1964, the existence of the Higgs Electron Muon boson was predicted to be an elementary Particles generated by the Higgs field H particle that is related to gravitationalNucleus force Proton Electron cloud Down quark Higgs boson (and mass). It took a state-of-the-art accel- Figure 2: erator to finally confirm its existence in Composition of the universe Figure 3: Elementary particles that shape the universe (Image courtesy of KEK) 2012. It is considered to be responsible for (Image courtesy of KEK)

Figure 9: With a circumference of about 27 km, the Large Hadron Collider is the world’s largest accelerator. It is operated by CERN in Geneva, Switzerland. (In comparison, the distance travelled by the Yamanote railway line that LHC control room Inside the LHC tunnel encircles central Tokyo is 34.5 km. Lake Geneva and © 2015–2017 CERN © 2015–2017 CERN Geneva Airport can be seen in the background of the photo behind the circular accelerator) © 2001–2017 CERN the mechanism that causes the respective ting light and discharging electricity. system shown in Figure 4. elementary particles to acquire a specific To overcome these challenges, pure mass. electrons and positrons (the antimatter of The groundbreaking mechanism electrons) need to be brought into collision of the ILC ILC: a linear collider that could with much greater energy. This is how the help unravel the Big Bang proposal for the development of a linear The ILC is an international proj- accelerator ILC came about (Figures 4 ect that is intended to allow researchers An accelerator is used to observe and 8). from Asia, North and South America, and phenomena at the interaction points where Saeki: In a sense, the ILC is a huge exper- Europe to collaborate in elementary parti- particles are brought into collision. This imental system that recreates the Big Bang cle research. Japan is the most promising experimental system may not seem to have inside it with the aim of unravelling the candidate for securing the project, and the anything to do with understanding the mysteries of the universe. Unlike circular mountainous areas of Kyushu and Tohoku universe, but observing phenomena at one models that can accelerate particles mul- have been named as candidate sites for the infinitesimally small point provides clues tiple times as they travel along their rings, construction of the accelerator. to unravelling the mysteries of the begin- a linear accelerator has only one chance With the Higgs boson having been ning of the universe and the origins of life. to bring particles into collision. The prob- discovered at the LHC in 2012, there are In other words, we can learn about the ability of a collision must be increased high expectations that the improved func- vast expanses of the universe by studying as much as possible to make up for this tionality of the ILC will help us take the the behavior of infinitesimally small ele- disadvantage. Consequently, collections of next step toward a new research theme. mentary particles. electrons and positrons must be focused Saeki: Starting in 1996, I spent six years In 2008, construction of the Large into dense beams. This function is fulfilled carrying out research at CERN. The tunnel, Hadron Collider (LHC), the world’s most by the dumping ring and the final focus where the LHC is today, used to house the powerful accelerator, was completed by the European Organization for Nuclear Research (CERN). This vast circular Figure 10: accelerator has a circumference of around The driving force behind linear Electric Electric field field 27 km, which is almost the same distance acceleration as the length of the Yamanote railway As shown in the figure, the ILC accelerates 1 Electron line that encircles central Tokyo. It was electrons with alternating electric fields Electric Electric this CERN accelerator that successfully (i.e., positive and negative). field field The exceptional designed energy observed the Higgs boson (Figure 9). efficiency for the high-frequency power in The LHC accelerates two proton Saeki: the L-band (1.3 GHz) is produced thanks beams travelling in opposite directions Electric Electric to superconductivity, with a temperature field field over the course of a number of laps before maintained at -271°C (2K) by cooling the Electron particles carrying great energy eventually superconducting acceleration cavity from 2 collide. the outside with liquid helium. Electric Electric Importantly, each proton is a combi- field field nation of three quarks. Basically, a proton is a mixture of particles. Conducting an analysis of how the behavior of particles Electric Electric changes as a result of their collision is field field complex and prone to errors. One disad- Electron (Illustration created based 3 vantage is that particles accelerated close on materials provided by KEK) Electric Electric to the speed of light by a circular accelera- field field tor lose a huge amount of energy by emit-

18 ULVAC ｜ No.67 (October, 2017) Large Electron–Positron (LEP) collider. the issue of workability and deliver excel- In those days, the accelerator was use to lent superconducting performance. In other conduct experiments where electrons and words, it may be possible for a supercon- positrons were brought into collision. I ducting accelerator to operate at the tem- studied the pair production of elementary perature of liquid nitrogen in the future. particles called W bosons using the LEP Such an advanced thin film technology collider. Later, CERN converted the LEP would help to reduce the size of super- collider into the LHC. Following my return conducting accelerators dramatically and to Japan in about 2003, I began working in slash production costs. We hope to develop earnest to turn the ILC project into reality. such a technology through joint research Even if the newly completed LHC discov- between ULVAC and KEK (see the col- ered the Higgs boson, questions regarding umn below). dark matter and energy would not be com- The acceleration of electrons (or pletely answered—that is why I believed positrons) by an alternating (i.e., not one Dr. Saeki stood next to a cryomodule that an even more upgraded accelerator way) electromagnetic field in the ILC is would certainly be necessary. carried out based on the mechanism shown To raise the energy of electrons (or in Figure 10. Technically, it is much easier Elementary particle physics research- positrons) by accelerating them in multiple to handle direct current, but accelerating ers around the world openly share their stages, the ILC consumes vast amounts of to a high speed using this would require research findings across borders. Through electric power. Furthermore, in order to a correspondingly high voltage, which in friendly competition, they strive to unravel efficiently harness a strong current, super- turn would cause internal sparks (basically the mysteries of the beginning of the uni- conducting technology is employed in the lightening) and destroy the accelerator. verse and the origins of life through tireless cavity units that accelerate the particles. As shown in the figure, the applica- research. These superconducting cavity units are tion of alternating current can accelerate The implementation of the ILC cooled with liquid helium. Thermal insu- particles without raising the voltage, there- project is extremely costly. Given this, the lation is ensured through the use of sur- by avoiding the generation of sparks. project cannot be realized without the full rounding cryomodules that resemble giant understanding and support of the Japanese thermos flasks. This is my specialist area Significance and mission of the public and government. (Figures 5–7). Even the groundbreaking findings ILC project implemented by Japan Superconducting acceleration cavity achieved by the ILC do not mark a defini- units are made of niobium, a supercon- as a leading scientific nation tive end to our quest for knowledge. Take ducting rare metal. Other outstanding Children and adults alike wonder dark matter and energy, for example. The superconducting materials called high-tem- about how the universe came into being more we know in science, the more unex- perature superconductors do exist at and what lies beyond the universe? plained fields of research emerge. Indeed, present, but most of these ceramic-like (or Research conducted using the ILC as soon as we reach one destination, it earthenware-like) materials cannot form attempts to answer genuine questions becomes a new starting point. Sooner or the complex, curved caterpillar-shape such as these. With a smile on his face, later, the ILC will need to be replaced by used for these cavity units. That is why Associate Professor Saeki says with abso- another accelerator. we use niobium as a superconducting pure lute certainty that the newly installed ILC It is no exaggeration to say that I am metal. Niobium is certainly an expensive contributes something more than just devoting all of my energy to implementing rare metal, but a significant cost reduction immediate and direct gains. the ILC plan. I believe that the ILC will is expected if a film of niobium can be Saeki: I have no doubt that, over the next be of benefit to the scientific researchers formed on the inner surface of a copper few years, the ILC will make an immense of the future, including those who are still mold. Similarly, applying a thin film of a contribution toward the advancement of in school today. It will certainly lay the high-temperature superconductor on the our scientific civilization. I am very confi- foundations for scientific advancement in inner surface of the cavity would resolve dent about its potential. Japan.

Tomohiro Nagata During my temporary assignment to KEK in fiscal 2012, I had the oppor- Manager, Advanced Material Research Section, tunity to work with Dr. Takayuki Saeki. Even today, I still draw on the time we Future Technology Research Laboratory, ULVAC, Inc. spent together assembling measuring instruments and engaging in deep discus- sions late into the night. A powerful tag-team Building on this experience and my human network from those days, my for the advancement of science current group is engaged in joint or collaborative research with KEK based on three themes. One is the joint research that we began in fiscal 2016 with Dr. Saeki regarding an accelerator component called the superconducting thin-film acceleration cavity. This research is aimed at validating and commercializing a theory predicting that accelerator performance can be significantly enhanced through the use of thin-film superconductors. In this research, KEK is able to leverage its knowledge of superconductivity and accelerators, while ULVAC contributes through its strong background in thin-film technologies. Lately, the application of thin-film technologies has begun to attract con- siderable attention. We consider this joint research with Dr. Saeki to present a great opportunity for us to demonstrate ULVAC’s technical sophistication. At this stage, we are carrying out a basic verification, after which we will forge Nagata and Dr. Saeki (left) stood in front of a ahead toward commercialization by overcoming the challenges we face one by superconducting acceleration cavity unit one.

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