3rd Open Meeting of the Belle II Collaboration Cosmic ray test for Phoswich option Insu Lee, Taeyoung Kim , Sunghyun Kim and ByungGu Cheon Hanyang University 7 July, 2009 3rd Open Meeting of the Belle II Collaboration

Outline Motivation Cosmic ray test Summary ECL electronics for Belle II

Phoswich option for Belle II A phoswich ('phosphor sandwich') is a combination of scintillators with dissimilar pulse shape characteristics optically coupled to each other and to a common PMT. Pulse shape analysis distinguishes the signals from the two scintillators, identifying in which scintillator the event occurred. CsI(Tl) Slow signal Pure CsI Fast signal Idea: re-use (possibly) un-damaged rear part of endcap CsI(Tl) crystals Merit as Belle II Endcap crystal option : * Radiation damage only to front ~10 cm of crystals * High energy signals  enough signal in CsI(Tl) crystals  do not lose resolution * Fast/Slow  another handle for shower correction by knowing shower shape * Fast trigger signal using fast signal  blind to beam background * Much cheaper than other options such as pure-CsI only, BSO or PWO-II

Cosmic ray test setup muon 5cm PMT (pure) 10cm CsI (Tl) 20cm PMT Plastic Scintillator 5cm PMT Plastic Scintillator CsI (Tl) 20cm (pure) 10cm Fedora core 6 FADC 400MHz Linux PC Phoswich PMT

Typical event shapes Two types of signals has been detected. Pure 는 412개 Tl 588개 Two types of signals has been detected. CsI(Tl) and pure CsI oriented signals

Compared with separated Xtals CsI+CsI(Tl) CsI+CsI(Tl) CsI(Tl) CsI

Summary / Plan Summary - Pulse shape discrimination is unclear. - Pure comp. seems to be smeared in Tl comp. - It seems re-emission of pure comp. in CsI(Tl). - Lots of works are needed to be realized. Plan - Try to test phoswich prototype at beam test facility.

ECL electronics for Belle II Most of electronics are considered to produce in Korea. - Trigger module prototype design is still going on. - Barrel shaper prototype has been produced. - Endcap shaper / Collector module / Preamp - We will develop them together with BINP group. Mass production - Trigger: FAM (60) / TMM (10) - Barrel shaper (400) / Endcap shaper(200) - Collector (60) / Preamp (2000)

Backup slides

sBelle calorimeter trigger Feature : Much simpler electronics chain (2 steps) than Belle More flexible trigger algorithm design than Belle 1st step (FAM) : 10MHz/12bit FADC + FPGA 2nd step (TMM) : cascade/partitioning FPGAs Bulky copper cables  52 optical fibers Simple monitoring scheme Simultaneous handling of CsI(Tl) and pure-CsI signals Current status : We now investigate fast shaping signal from new Shaper. FAM core firmware algorithm has been tested. TSIM MC study has been performed w/ g4superb. Plan : FAM/TMM prototype design is still going on. Basic test of Shaper/FAM/TMM readout chain Under real environment before Belle shutdown Belle sBelle