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SksMinus status. SKS meeting 2008/1/18 白鳥昂太郎. SksMinus setup. SksMinus. SDC1~4 : Beam position measurement. STOF : Time-of-flight SAC & BAC: K - beam veto and p - ID (n=1.03). Background Veto. _. SMF : m - from K - → m - + n SP0 : p - from K - → p - + p 0.
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SksMinusstatus SKS meeting 2008/1/18 白鳥昂太郎
SksMinus setup SksMinus • SDC1~4 : Beam position measurement • STOF : Time-of-flight • SAC & BAC: K- beam veto and p- ID (n=1.03) Background Veto _ • SMF : m- from K- → m- + n • SP0 : p- from K- → p- + p0 Target ~20 g/cm2
SksMinus elements Test and production in progress • Drift chambers : BD(SDC3,4), SDC1,2 • Timing counters : STOF, BH2 • Beam decay veto counters : SMF Design • Aerogel Cherenkov counters : BAC, SAC • Beam decay veto counters : SP0 • Targets : 4He target
Drift chambers BD (SDC3&4) SDC1&2
BD repair status All sense wire exchange : 20 mm → 25 mm • Freiberg (XX,UU,VV) • 3 layers finished (X,U,V) • The other 3 layers : repair in Jun → Test in Feb • BNL (XXXX,UU,VVV → XX,UU,VV) • Feb ~ Apr : repair • Apr ~ May : test Repair routine is fixed.
BD status • Plateau : 1950~2250 V → 2150 V operation • Uniform wire tension
BD test • Efficiency and resolution test by cosmic ray • FUJI beam line ? • DAQ with TKO MHTDC • Test and study how to use TKO MHTDC • 3377 by CAMAC is easy… Goal : Less than 400 mm (rms) resolution (~300 mm is possible) *Where do we test ? ⇒ East counter hall ?
SDC1 and 2 • SDC1 : SksPlus SDC2 (400×200 mm2, 3mm spacing, xxuuvv planes) • After Okamura’s chamber ? • SDC2 : Old SDC2 (560×150 mm2, 5 mm spacing, xxuu planes) • Test and repair from Jun (or after ?)
Frame and readout electronics • Frame (Upstream and Down stream) • Not yet designed : SKS configuration, common frames ? • Plan of production : From Jun • Readout electronics • Fryeburg : Special preamp with modification • BNL : Present readout with modification • SDC1 and SDC2 : Present readout ⇒ TKO TDC
3 4 8 11 12 1 2 5 6 7 9 10 Schedule Freiberg repair test BNL repair test SDC2 repair test SDC1 ????? Frame Design Production Readout (cable, connector) Design Production and test
STOF • BT cannot be used…. • Dt ~100 ps(rms), 30 cm attenuation length • Present SKS TOF counter • Dt ~80 ps(rms), 100 cm attenuation length ⇒To add Present SKS counters • Present 15 segments ⇒ STOF 30 segments • + 15 segments Frame design and production : From now • The similar design with present SKS TOF frame BH2 and BP : Just production
SMF (K→m n veto) SMF Timing counter • FTOF(KURAMA) + BT • BT×14 segments Iron block • Iron beam shield • Frame design is not difficult. BT test⇒ Usable. FTOF Iron block BT
BH2 & BP • BH2 : Start counter (time zero) • 1 segment with booster PMT • BP : Beam decision counter • 1 segment : Fiber readout ? BAC1 BAC2 SAC Beam BH2 Target BP
Design SP0 SAC, BAC Target
SP0 (K→p p0 veto) Beam decay background veto Performance • 80% of p events rejected (enough) Accidental hits from background • Multi-layer hit, total energy deposit • OK : Neutron, low energy gamma, mesonic-decay • Other charged particles ⇒ Charge veto • NO : Mesonic-decay : p0 (~20% kill @ 4LHe) SP0 : p- from K- → p- + p0
3 4 8 11 12 1 2 5 6 7 9 10 SP0 design • Range counter (E559) based • Scinti、PMT: OK + (Iron shield) • Light guide or Fiber ? • Lead : How to get (600 kg) • Frame : How to fix lead ? design easy test ? production Range counter disassembly
AC counters SAC, BAC
AC design Index : n=1.03 ~4 photons • BAC1,2 • 160×30×75 mm • SAC1 : • 300×90×75 mm • SAC2 : • 360×100×75 mm With 2 inch fine mesh PMT (F~72 mm)×8 Inside : White box, w/ or w/o reflector Design and test start from Mar
3 4 8 11 12 1 2 5 6 7 9 10 AC test and schedule • To test largest size (SAC2: 360×100×75 mm) • Cosmic ray test • Efficiency by LNS beam • Inside w/ or w/o reflector • Other In-beam test ? test test test test design production improvement improvement improvement
4He target Target size : f150 mm×250 mm • No progress • Just start to design (E549, E570 target)
Summary • Three important elements • BD in progress : 1 detector finished in February. • SP0 design will be finished soon. • He target is just designed stage. • Other elements • Timing counters are production stage. : STOF, SMF, BH2, BP • AC counters (BAC and SAC) are designed stage.
SKS移動 : Pivot 支持装置を設置 支持装置(L字) 設置前 設置後 回転中心 ピボット。ここに回転中心用ジグを設置 To produce SksMinus支持装置(L字)
SKS移動 : 油圧ジャッキ, 腕 油圧ジャッキ用の腕 設置前 設置後 腕 油圧ジャッキ 押すときには上下に動かないように固定するジグが必要。SKSの壁に付ける。
Readout channels • DC : total 2608 ch (T) • SDC1 (xxuuvv) : 128 ch×6 = 768 ch • SDC2 (xxuu) : 112 ch×4 = 448 ch • SDC3 (xxuuvv) : 108 ch×2 + 120 ch×4 = 696 ch • SDC4 (xxuuvv) : 108 ch×2 + 120 ch×4 = 696 ch • Timing counter : total 64 ch (A&T) • STOF : 30 segment : 60 A&T • BH2, BP : 2 ch×2 = 4 A&T • Veto counter : total 88 ch (A&T) • SMF : 24 + 14 segments : 38 A&T • SP0 : 5 segments×10 layers : 50 A&T • AC : total 8 ch (A&T) • SAC : 2 ch×2 = 4 A&T • BAC : 2 ch×2 = 4 A&T TKO TDC 32 ch TDC×82 TKO ADC 16 ch ADC×10 HR TDC 16 ch TDC×10