Two-Dimensional Read out of Large Muon Drift Tubes

Research Project

Project/Area Number	60460020
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	核・宇宙線・素粒子
Research Institution	Osaka City University
Principal Investigator	TAKAHASHI Tamotsu Osaka City University, Faculty of science, 理学部, 助教授 (20047137)
Co-Investigator(Kenkyū-buntansha)	SATO Takahiro National Laboratory for High energy physics, 助教授 (10013418) OKUSAWA Tooru Osaka City University, Faculty of Science, 理学部, 講師 (60047397) HIGASHI Shigeru Osaka City University, Faculty of Science, 理学部, 教授 (50046786)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥7,000,000 (Direct Cost: ¥7,000,000) Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000) Fiscal Year 1985: ¥6,000,000 (Direct Cost: ¥6,000,000)
Keywords	Muon detector / Drift chamber / Zig-zag delay line / Two-dimensional readout / リミテッドストリーマー / ディレイライン読み出し
Research Abstract	The feasibility of using zig-zag delay line to measure the coordinate along the sense wire from a drift tubes was tested. Two prototype chambers made of a recutangular aluminium tube with the cross section of 10cmx5cm and length of 140cm have been constructed. In this tube a chamber(type-1) has a sense wire at the center and a shifted zig-zag delay line strip on the bottom plane. Type-2 has the same strip at the center vertical to the plane and two sense wires at the center of the section separated by the strip. The sense wire is gold plated tungsten 100 <mu> m diameter. The delay line strip is photo-etched on both sides of copper-cladded Kapton strip. The impeadance is 60 <OMEGA> , the delay time is 3.2ns/cm and the total delay time is 450ns. The pulse height induced on the delay line is about 1/10 of the sense wire. Then, the chamber operated in the limitted-streamer mode. A mixture of 70% Argon and 30% iso-Butane was used. The detection efficiency was 98% at 4.3kV. Well-collimated electrons of Ru come through the chamber to scintillation counter. A charged particle generates three signals from sense wire and the two ends of the delay line. Times of these signals were measured by 10 bit, 1ns resolution TDC. The propagation velocity of the induced pulses in both distributions of the delay line is obtained to be 3.28 <+!-> 0.01ns/cm. The position accuracies along the sense wire are sigma of 4.7mm(type-1) and 2.7mm(type-2). The other coordinate was obtained by measuring the time difference between the sense wire and the scintillation counter. A position accuracy is sigma of 1mm. Pulse heights from the ends were measured using 100MHz FADC to measure attenuation of induced pulse. The attenuation factor obtained is 168cm.