Effect of magnetic field B Hide PMT from

Effect of magnetic field B ü Hide PMT from charged particle ü PMT for strong magnetic field (～ 4000 gauss) Top : http: //www. phenix. bnl. gov/phenix/project_info/integration/config_management/envelope_control Bottom : PHENIX Conseptual Design Report , Chapter 4 Magnets (1993)

PMT selection R 5924 fine mesh PMT ü Operate in high magnetic field ü High gain ～ 400μA ( cf. R 3809 MCP type ～ 1０μA ) l Rise Time ‥‥‥ 2. 5 nsec l T. T. S ‥‥‥ 440 psec l Anode Effective Area ‥‥‥ Φ 39 mm (min) l Current Amplification at 0 Tesla at 0. 5 Tesla at 1. 0 Tesla ※ HAMAMATSU PHOTONICS K. K.

Light Guide 100 % ? % Cross section scintillator PMT ① inside ② outside L cm Scintillator face 2 cm× 8 cm PMT face 4 cm× 4 cm ü Few difference between inside rod and outside and get many photon when L=10 cm

Light Guide ( details ) 100 % Cross section ? % scintillator PMT inside outside Scintillator face PMT face 2 cm× 8 cm 4 cm× 4 cm L cm ① no reflection ② rectangle ③ fish tail ④ rectangle + fish tail 4 cm L [cm]

Expected Time Degradation cross section scintillator ‥‥ ①outside‥‥‥ ‥‥･②inside‥‥‥･ PMT 2 cm× 2 cm × 4 x [cm] ・Scintillator should be divided into four. ③ 2 cm× 8 cm

Expected T 0 Resolution Light guide PMT ⊿TL charged particle scintillator ⊿TR x [cm] T 0 resolution : (x=50 cm)