SAKUDA Makoto High Energy Accel. Research Organ., Insti. Of Particle and Nuclear Studies, Associate Professor, 素粒子原子核研究所, 助教授 (40178596)
TAMURA Norio Niigata Univ., Grad. School of Sci. and Tech., Professor, 大学院・自然科学研究科, 教授 (00025462)
|Budget Amount *help
¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1998 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1997 : ¥1,700,000 (Direct Cost : ¥1,700,000)
We studied two methods, using a wave length shifter bar and dissolving wove length shifter in water, to detect Cherenkov lights from a few cm thick water by charged particles.
In the case of using a wave length shifter bar, we tested alminized-mylar, tyvec, and goatee as reflector. We measured angular distribution of diffused reflection for tyvec and goatee. We made a simulation program to estimate the number of photo-electrons at the end of 5 cm x 5 cm x 300 cm tube, considering the wave length distribution of Cherenkov lights, the angular distribution of diffused reflection, and the wave length distribution of water permeability. According to the simulation, for the 5 cm x 5 cm x 300 cm tube, we get more lights for diffused reflector than for non-diffused reflector (alminized-mylar), at the end.
In the case of dissolving wave length shifter in water, dimethyl-POPOP (0.13g) with a solvent of dioxane (50ml) and methanol (30ml), and amino-G acid were tested. The former was insoluble. Containing the materials described above in glass, we compared the number of photo-electrons by Cherenkov lights with that from pure water. The number of photo-electrons was twice.
The simulation says that we can expect small position dependence of the number of photo-electrons and uniform particle identification ability against position, if we use wave length shifter bar for 5 cm x 5 cm x 300 cm tube.