[en] Effect of a magnetic shielding for a phototube of 3'' diameter attached to a lead glass counter has been studied using permalloy shielding cases with two kinds of shapes. Both cases show sufficient shielding effect with magnetic field up to around 30 gauss. (author)

[en] In this paper development of plastic scintillation fibers (PSF), a calorimeter using PSF and its readout system with position sensitive photomultiplier tube (PSPMT) is reported

[en] The measurement of the K⁺n elastic and the charge exchange reactions is interesting from the view point of studying the reaction dynamics of hadrons. Regge theory is considered to work even at low energy region down to around 1 GeV/c for the exotic channels. It makes some predictions as to the values of P-parameters for the K⁺ nucleon reactions. The author presents measurements made of these parameters at the momenta 1.06, 1.28, 1.39 and 1.49 GeV/c. (Auth.)

[en] A conceptual design of a large-aperture solenoidal magnet detector is presented with primary emphasis on large p/sub t/ phenomena. The physics goals of this detector are, as in many other proposals, to detect weak bosons W/sup +-/ and Z⁰, high mass flavors, heavy leptons, Higgs particles, and high p/sub t/ jets, and to check QCD, etc. A solenoidal configuration was chosen rather than a dipole or a toroidal one because with a quite uniform axial field, (1) it will be quite easy to make a fast high p/sub t/ trigger, (2) data analysis will be much simpler, (3) coupling to the beam is minimal, and (4) the detector has a large p/sub t/ coverage

[en] The high rate of particles per unit area and time produced at ISABELLE at full luminosity (10³³ cm^-2 sec^-1) calls for the usage of devices with the shortest space and time resolution. Hodoscopes made of thin scintillation fibers will satisfy such requirements. The short resolution time (3 to 4 nsec) of the scintillator can provide a fast trigger and strobing gates for shower detectors used in same experiment. It will also keep the number of accidental coincidences to a minimum. If read out with microchannel plates or avalanche photodiodes, such hodoscopes can be readily used in a magnetic field. Their fine granularity could be used to provide spatial position information for track reconstruction or for pretrigger schemes based on crude pattern recognition. For example, with a luminosity of 10³³ cm^-2 sec^-1, the expected particle yield is about 10⁸ particles/sec in a solid angle covering the polar angular region of 45⁰ < theta < 135⁰. Most of these particles produced, however, have very low transverse momentum (p/sub perpendicular to/ < 5 GeV/c). Therefore, the hodoscope information could be used to provide a pretrigger rejecting low p/sub perpendicular to/ tracks on the basis of a crude determination of the sagitta of the trajectory in a magnetic field. Another example of a case in which fine granularity is essential is that of small-angle scattering experiments, which require angular resolution of a fraction of a milliradian. A brief survey of a few typical detectors discussed in previous Summer Workshops is presented. Its purpose is to look into the usage of fine-grain hodoscopes in each detector configuration. Four cases are considered: the axial-field magnetic spectrometer (ISR version), the lepton detector, the wide-angle spectrometer, and the detector for small-angle scattering

[en] Some processes in the electron-positron interaction in the TRISTAN energy range were studied using the QCD Monte Carlo program written by Ali et al. The processes which were studied are; electron + positron → one photon → QQ(bar), QQ(bar)g, QQ(bar)gg, where Q = u, d, s, c, b Fquarks and g is a gluon; electron + positron → one photon → tt(bar) → X, where X = three gluons, weak decay products, Higgs + one photon, and two gluons + one photon; electron + positron → one photon → heavy lepton pair; two photon processes. The general properties of final states in QCD jets are displayed, which include single particle spectra, multiplicity, sphericity, spherocity, and thrust distribution. Based on the analysis, several remarks are made. It is very hard to find the D peak in the invariant mass sperctra for the momentum resolution of 0.3 % of the momenta. One-photon processes can be well separated from two-photon processes. Electron can be identified with a shower counter. The measurement of the leading kaon momentum spectra may be better for the study of t-quark decay mode. Energy resolution should be better than 10 % of √E if it is necessary to see the photon peak corresponding to the Higgs + photon process in the inclusive photon spectrum. Hadron calorimeter makes the one photon peak in a visible energy spectrum narrower, and improves the one- and two-photon process separation. (Ito, K.)

[en] The civil engineering aspect of the construction of an accelerator complex of a hadron collider with the beam energy larger than 30TeV was studied. The collider will consist of about 10,000 superconducting magnets accommodated in an underground tunnel of diameter as large as 30km. The complex has a booster with a beam energy of one TeV. One of the possible places for the construction of the accelerator complex will be the area of Abukuma district in Fukushima Prefecture. The construction cost of the tunnel was estimated by experts to be about 90 billion yen including the approach roads. This is only three times as much as the cost of the TRISTAN tunnel whose length is about 3km. This cost is consistent with the estimated cost of the LEP tunnel. It was also estimated that the construction can be finished in four years. (Aoki, K.)

[en] The differential cross-section for the reaction γp→π⁺n was measured using the bremsstrahlung beam of the Bonn 2.5 GeV electron synchrotron. The pions were detected and momentum analysed in a multichannel magnet spectrometer. Data reduction resulted in 1278 measured cross-sections which are presented as energy distributions at six laboratory angles between 180 and 95 . The range of laboratory photon energies extended from 0.3 to 2.1 GeV. The statistical accuracy is better than 3 percent, the systematic error is about 5 percent. The data are compared with other experimental results and predictions of a phenomenological analysis. These cross-sections are the result of a measurement program which was started in the seventies. Further results will be reported in forthcoming publications. (orig.)

[en] The performance of a photomultiplier tube with transmissive dynodes was examined. We found that the amplification gain was higher than 10⁴ even in a magnetic field of 7.8 kG. The energy resolution for 662 keV gamma rays from ¹³⁷Cs was 12% fwhm measured using a NaI crystal at 7.8 kG. The time resolution was as good as about 200 ps at 7.8 kG for the light generated by 2 GeV pions when they passed through a 1 cm thick scintillator mounted on the tube. (orig.)

No abstract available