No abstract available

No abstract available

[en] This paper describes the use of cathode-window space of a proportional wire chamber for a better energy resolution. By providing a drift field in this gap, the whole thickness of the chamber was made sensitive. As a result, the pulse height resolution for minimum ionizing particles substantially improved over the conventional results. (author)

[en] We propose a 4π magnetic spectrometer as a universal detector at TRISTAN E⁺E^- collider. A part of the simulated performance is reported here; the detection of hadronic one-photon-annihilation events and the search of the fundamental scalar particle. (author)

[en] The Japan electron-positron Linear Collider (JLC) project aims to directly probe the physics behind the presently observed elementary particles that are successfully but in a good part phenomenologically described by the Standard Model. A long-term physics program is made possible at the planned accelerator complex, and it is to start early from the sub-TeV energy region. Summarized here are the remarkable progress made in the area of accelerator R/D and the initial results of a systematic study of experimental prospects. (author)

[en] Many of the elemental processes following an electron-positron collision involve the production of unstable paired particles. To investigate the elemental and secondary processes accompanying a collision, it is necessary to make a simultaneous observation of a large number of various high-energy particles. The system for the experiment comprises a magnetic spectrometer and a shower counter. The spectrometer consists of a large tracking chamber and a superconducting solenoid. The chamber is placed in a static magnetic field to detect a charged particle passing various detection points. The set of points where the particle is detected represents its path. A drift chamber is adopted which is designed taking into account the following three processes: (1) formation of ionizing electrons along the particle path (track generation), (2) forced transfer of electrons due to static magnetic field (electron drift) and (3) electron amplification by local strong electric field after the transfer (signal generation). If the drift rate is known, a point where the particle passes can be determined from the drift time from (1) to (3). A high-energy particle produces shower after entering a high-density material. The energy of the particle can be estimated from the amount of the shower, which is represented by, for example, the total number of secondary particles produced. (Nogami, K.)

[en] Any successor to PETRA and PEP colliders was expected to extend the energy range to the region where the weak interaction effect becomes sizable in annihilation process. The aim was to reach the level, at which the all round study of the standard model can be performed in a clean system of e⁺e^- collision. Also it was aimed to explore the energy region where top quark pair production is likely. Considering the available site for accelerator construction and the expected size of the electroweak interference effect, the target energy was set at 60 GeV at the lowest. TRISTAN-1 experiment is a big initial step in the long range physics program. The laboratory established the plan to move on to TRISTAN-2 (B Factory) project. The TRISTAN accelerator including the main storage ring, the time sequence of storage ring operation, three experimental groups of AMY, TOPAZ and VENUS, and so on are explained. The experiments on basic annihilation process, the search for new particles, the electroweak interaction, QCD studies and so on are reported. The optimum TRISTAN ring was estimated as 3 km in diameter, but the largest possible size in the site was 1/3 of that. Hard decision was made to equip the ring with unusually many accelerating RF cavities and to apply superconducting technology. (K.I.)

[en] We report on the construction and performance of a large-aperture magnetic spectrometer used for pion-proton scattering experiments at KEK (the National Laboratory for High Energy Physics, Tsukuba). By a combined use of a large magnet and many wire chambers, differential cross sections and polarization parameters were measured over wide energy and angular ranges with high angular resolution, highest statistics and lowest background contamination. We describe here individual detectors and the overall performance. (author)

[en] The requirement and expectation for the ionizing radiation detectors used for various research fields are described. In the field of elementary particle physics, secondary vertex detectors have been developed. The vertex detectors have good position resolution to detect the decay of elementary particles. Large volume track detectors and total energy detectors (calorimeters) were also developed. In the field of nuclear physics, it is necessary to have information on the kind of radiation, energy, spatial distribution and the time of detection. The polarization, multiplicity and others are also required. Magnetic spectrometers with detectors were designed. The detectors based on the tunnel effect of super conductors were proposed, but are not yet in use. For gamma-ray spectroscopy, Ge detectors have been widely used, and BGO detectors will replace NaI(Tl) detectors. For the detection of heavy-ions, ΔE-E detectors have been used. In the field of space physics, the detection of weak events is important. X-ray detectors, gamma-ray detectors and particle detectors for this purpose are introduced. In the field of the application of atomic energy, there are three main fields such as the use of atomic energy, the applied use of nuclear radiation, and the radiation protection. Detectors have been developed according to the requirement from these three fields. In the applied use of synchrotron X-radiation, the development of position sensitive detectors are required. It is also necessary to develop detectors for each research project. (Kato, T.)

[en] A multi-pixel photon sensor with single-photon sensitivity has been developed. Based on a hybrid photo-detector (HPD) technology, it consists of a photocathode and a multi-pixel avalanche diode (MP-AD). The developed HPD has a proximity-focused structure, where the photocathode and MP-AD face each other with a small gap of 2.5 mm. The MP-AD, which has an effective area of 16 mmx16 mm, is composed of 8x8 pixel and has been specially designed for the HPD. The maximum gain of the HPD is 5x10⁴, sufficiently high to detect single photons with a timing resolution better than 100 ps. Up to four photoelectrons can be clearly identified as distinct peaks in a pulse-height spectrum, thanks to the low-noise characteristics of the HPD. It is also demonstrated that the HPD can be operated with good performance in a magnetic field as high as 1.5 T