KoreaJapan workshop on nuclear and hadron physics at

Korea-Japan workshop on nuclear and hadron physics at J-PARC 9/22 -9/23 , 2011, Seoul Status of the detectors for the E 18 Mijung Kim Seoul National University On behalf of J-PARC E 18 Collaboration

L n → nn(Gn) Lp → np(Gp) LNN→n. NN(G 2 N) 12 C(p+, K+)12 LC SKS Spectrometer K+ SDC Exp. target BDC Q 13 Q 12 K 1. 8 Beam Spectrometer p+ Q 10 D 4 Q 11

E 18 Setup Target Beam SKS ck ba C D S SKS BDC Shifted 30~55 cm

ed t f i h s m To SKS Bea No lightguide!!! E 18 Setup

Test for Neutron Detector which has only one light guide

E 18 Setup T 2: [0. 4(T) x 4(W) x 20(L) cm 3](12) , [0. 4(T) x 4(W) x 25(L) cm 3](8) as d. E detector , as fast timing counter T 4 Side Veto [2(T) x 10(W) x 100(L) cm 3] (32) x 8 segments as charged particle veto as range counter for proton T 3 T 2 T 3 : PDC T 2 T 4 : [5(T) x 20(W) x 100(L) cm 3] Target Beam x 6 layers x 4 seg/layer (96) as Neutron counter arrays as range counter for proton Side VETO : 150 mm Backside view [1(T) x 15(W) x 100 (L) cm 3] x 2 sides (8) as side veto to reject passing through particles increase the acceptance of charged particle PDC : Drift chamber(2)

T 2 [4(T) x 40(W) x 200(L) mm 3](12) , [4(T) x 40(W) x 250(L) mm 3](8) [mm] To decrease proton detection threshold!!!! T 3 We started to mount T 2 counters. We already have plastic scintillator, light guides and PMT for T 2. All 20 counters are new ones. T 2 counter is employed right after the target as the TOF start counter(TOF between T 2 and T 3) and the d. E/dx counter for the charged PID analysis Time resolution is s~ 50 ps

T 3 T 4 [20(T) x 100(W) x 1000(L) mm 3] x 8 segments (32) T 3 T 2 T 3 [mm] T 3 counter is employed as the TOF stop counter(between T 2 and T 3) for charged PID analysis. It is also used as a charged veto counter for neutral particle analysis. The length and number of the segments were determined to cover T 4 counter sufficiently in order to be used as the charged veto counter Time resolution is s~ 100 ps We need total 32 counters. We will reuse 21 sets of counters which were used in KEK E 462/E 508. We already have PMTs and light guides for T 3. But we need more 11 plastic scintillators.

T 4 [50(T) x 200(W) x 1000(L) mm 3] x 6 layers x 4 seg/layer (96) T 4 T 4 [mm] T 4 counter is employed as the neutral particle counter and range counter for proton. The total thickness of the scintillators is 30 cm which has about 30% of neutron detection efficiency at 60~80 Me. V energy region. Time resolution is s~ 200 ps We need total 96 counters. We will reuse 54 sets of counters which were used In KEK E 462/E 508. We already have plastic scintllators and PMTs for T 4. But we need more 14 light guides.

Side veto Side Veto [10(T) x 150(W) x 1000(L) mm 3] x 2 sides (8) To reject passing through particles -> increase the acceptance of charged Side veto particle. It covers three layers of Neutron detectors, 15 cm. Because Maximum range of charged particle(Emax~150 Me. V) is 15 cm, It is enough We need 8 side veto detectors. We have all plastic scintillators, light guides and PMTs. All 8 detectors are new ones.

In KEK North Counter Hall(Jan. 2010) PDC 4 mm drift length, intrinsic position resolution s~340 mm PDC Top+Bottom (two sets) Typical Cathode Typical anode Anode plane Top Bottom X-1 all OK 3 wires cut X’-1 8 wires cut all OK Y-1 1 wire cut all OK Y’-1 2 wire cut 1 wire cut X-2 all OK X’-2 31 wires cut 1 wire cut

Status on June 23, 2011(KEK North Counter Hall) PDC T 3/T 4 T 4(Neutron detector)

Summary Dete ctors size Req. Have Size(cm 3) Req. Have T 2 3 /4 “ 40 43 20 x 4 x 0. 4, 25 x 4 x 0. 4 12 8 14 12 40 40 T 3 2” 64 64 100 x 10 x 2 32 21(-11) 64 64 T 4 2” 192 209 100 x 20 x 5 96 104 192 178(-14) Side Veto 2” 16 16 100 x 15 x 1 8 16 16 16 PMT Plastic Scintillator Light Guide We need 11 more T 3 Plastic Scintillator (100 x 10 x 2 cm 3) and 14 T 4 light guides We have 312 PMTs!!!!!!! Except for Time Zero counter

E 18 Setup T 2: [0. 4(T) x 4(W) x 20(L) cm 3](12) , [0. 4(T) x 4(W) x 25(L) cm 3](8) as d. E detector , as fast timing counter T 4 Side Veto T 3 : T 3 [2(T) x 10(W) x 100(L) cm 3] (32) x 8 segments as charged particle veto as range counter for proton PDC T 2 T 4 : [5(T) x 20(W) x 100(L) cm 3] Target Beam x 6 layers x 4 seg/layer (96) as Neutron counter arrays as range counter for proton Side VETO : 150 mm Backside view [1(T) x 15(W) x 100 (L) cm 3] x 2 sides (8) as side veto to reject passing through particles increase the acceptance of charged particle PDC : Drift chamber(2)

Target

E 18 Setup SKS

SKS ck ba SDC BDC E 18 Setup Shifted 30~55 cm

E 18 Setup T 4 side. Vet o T 3 PDC T 2 am e B SKS