Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants|
|Research Institution||TOKYO INSTITUTE OF TECHNOLOGY|
ASAHI Koichiro(1996) Tokyo Inst.Tech.Appl.Physics Asosiate Professor, 理学部, 助教授 (80114354)
永井 泰樹(1995) 東京工業大学, 理学部, 教授 (80028240)
NOGUCHI Tutomu Department of Quantum Radiation Electrotechnical Laboratory, 量子放射部, 主任研究官
嶋 達志 東京工業大学, 理学部, 助手 (10222035)
旭 耕一郎 東京工業大学, 理学部, 助教授 (80114354)
|Project Period (FY)
1995 – 1996
Completed(Fiscal Year 1996)
|Budget Amount *help
¥6,900,000 (Direct Cost : ¥6,900,000)
Fiscal Year 1996 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1995 : ¥6,200,000 (Direct Cost : ¥6,200,000)
|Keywords||deuteron photo-disintegration / Compton backscattering of laser / drift chamber / meson exchange currents / ciuculary polarized light / angular distribution / trajectory of charged particle|
1) Construction of the time projection chamber.
The time projection chamber was newly constructed. Since the deuteron gas target costs very much, and also the energy of the proton emitted from the deuteron photodisintegration is very low leading to the short stopping range, we had to develop the chamber, which can be operated at low pressure of the gas target. Therefore, the chamber should be evacuated up to the extremely high vacuum with very few leakage.
2) Performance of the time projection chamber :
the performance of the time projection chamber was studied by using the alpha-ray source as discussed below.
2.1) Detection efficiency of the charged particle ;
The efficiency was more than 99.5% under the following conditions of the chambar. Namely, the high voltages of the anode wire and field wire were +1500V and -2000V,respectively at the gas presure of 700 torr.
2.2) Drift velocity ;
The average velocity was about 0.55(3)cm/micro seconds, and it depends on the strength of the electric field.
2.3) Energy resolution ;
The resolution was 5.8% for the signal of the energy loss of 67 keV,and the linearity of the pulse height vs. the energy was quite good.
2.4) Time resolution ;
The time resolution was 32 nano-seconds, which corresponds to the position resolution of the z-direction of 0.18 mm.
3). Construction of the purified gas circulating system :
In order to operate the time projection chamber・properly it should be used in the experimental conditions free from the impurity gas, caused either by the leakage of the system or the out gas of the system. Therefore, we constructed the closed gas circulating system with the gas purified equipment, and thereby we can provide the purified gas to the chamber. Consequently, the chamber can be used for a long term experiment without having any problem.
4). Construction of the data taking system :
The data taking program was made.