Grant-in-Aid for Scientific Research (A)
|Research Institution||KANAGAWA UNIVERSITY|
NISHIMURA Jun Kanagawa Univ.Industrial Eng.Professor, 工学部, 教授 (40013619)
YAMAGAMI Takamasa ISAS System Eng.Associate Professor, 助教授 (40013718)
TORII Shoji Kanagawa Univ.Physics Associate Professor, 工学部, 助教授 (90167536)
立山 暢人 神奈川大学, 工学部, 助教授 (30102239)
KASAHARA Katsuaki Kanagawa Univ.Information Associate Professor, 工学部, 助教授 (00013425)
桜井 邦朋 神奈川大学, 工学部, 教授
YOSHIDA Kenji Kanagawa Univ.Industrial Eng.Research Associate, 工学部, 助手 (90260984)
田村 忠久 神奈川大学, 工学部, 助手 (90121361)
TAMURA Tadahisa Kanagawa Univ.Physics Research Associate (90271361)
|Project Fiscal Year
1993 – 1996
Completed(Fiscal Year 1996)
|Budget Amount *help
¥29,100,000 (Direct Cost : ¥29,100,000)
Fiscal Year 1996 : ¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 1995 : ¥4,400,000 (Direct Cost : ¥4,400,000)
Fiscal Year 1994 : ¥4,900,000 (Direct Cost : ¥4,900,000)
Fiscal Year 1993 : ¥16,400,000 (Direct Cost : ¥16,400,000)
|Keywords||ELECTRON / COSMIC RAY / SUPER NOVA / ACCELERATION / SCINTILLATING FIBER / BALLOON / IMAGING / HIGH ENERGY / 電子 / 宇宙線 / 超新星 / 加速機構 / シンチファイバー / 気球 / イメージング / 高エネルギー / 加速 / 陽電子|
We have successfully developed BETS (Balloon Borne Electron Telescope with Scintillating Fibers) which was flown by balloon for the observation of cosmic electrons with energies from 10GeV to a few 100GeV.A new aspcet of the origin and propagation of high energy electrons is investigated by comparing the the observed energy spectrum with those expected by a diffusion model. BETS has also capability to observe the TeV electrons for a few years in space, and we expect such an observation in near future. Summary of yearly results is presented in the following.
1993 : Prototype of BETS and the flight test
We have carried out simulations to study a detector design which has the best performance for observing the high-energy electrons. The basic performance of scintillating fibers (SciFi) was tested by using accelerator beams. The effective area of detector is 28cm*28cm. Nuclear emulsion was also used for confirming the capability of position resolution, electron detection and charge resolutio
n. A test balloon-flight was done on September to prove the total performance including the electronics and the telemetry system.
1994 : Improvement of BETS and the second flight
By the test, some improvements were required on the image intensifier, the telemetry system and the trigger logics. A technique for analysis of the CCD image to reconstruct shower profiles was confirmed by using the observed events in the second flight.
1995 : BETS-2 and the third flight
The detector was considerably improved by incorporating two image-processing systems to detect shower profiles independently from x and y side. The BETS-2 which was flown for 7.5 hours at an altitude more than 36km, detected showers with the frequency of 1.6Hz. It is confirmed that the rejection power of the background protons is better than 1/2000. Almost all of showers over 50GeV were identified in emulsions at the positions within an error in which showers were observed with SciFi's. The electrons which identified with SciFi's was remarkably confirmed by analysis of emulsions.
1996 : Accelerator test for the calibration of BETS-2
An accelerator test of BETS-2 was carried out at CERN-SPS to confirm the detection capability of electrons and the energy resolution Energy spectrum of electrons from 10GeV to 100GeV is derived by the observed events with BETS-2 calibrated by the accelerator test. Less