Status Report for E391a (Continuation of the previous PAC on April) G.Y.Lim IPNS, KEK Group Meeting at the JINR 26 th – 29 th July 2003 Dzhelepov Laboratory of Nuclear Problems

After the previous PAC Start assembling the front barrel Continuous fabrication of the central barrel Evacuation test of the downstream section

E391a Detector Upstream section Downstream section Middle Section

Upstream Section Module fabrication was done – Dec Instrument for assembling was fabricated – Collaboration work with KEK machine shop Start assembling - August 2003 – Will take one month Evacuation/cosmic test will be done Sep. 2003

Slide show for FB assembling 5 th August 2003

Continuously 22 nd August (Expected)

CC02 Shashlik type of beam counter Arrived at KEK on 4 th July from U. of Chicago Beam test at pi2 July 2 nd ~8 th, % 1GeV, 10 p.e./MeV deposit (Very preliminary !!!)

After CC02 installation ・・・ Aiming to finish by the end of August

Middle section Module fabrication – Final stage

50 plates/week Finish at the middle of Sep.

Stacking on every Wed. Working more than 8 person End of September

Middle section Module fabrication – Final stage Vacuum vessel is being constructed – Competition bid – Hitachi Zosen Ltd. – Will arrive at KEK at the end of Oct Assembling scenario was fixed – Collaboration work with Entek Assembling will be done by the middle of Dec. 2003

Downstream section Assembling was finished – Sep Beam test (Engineering run) – Oct. – Dec Evacuation test – June 2003 – First time of operation for calorimeter in vacuum – Test for the water cooling mechanism

Cooling System Control PMT temperature within 1 0 C with circulating water

Installation of the cooling system

Temperature Measurement Divider CsI

We got clear Cosmic response 5 0 C Cooling water10 0 C Cooling water 15 0 C Cooling water20 0 C Cooling water ｐ Q/cm

Temp. dependency Cosmic Peak position Cosmic Peak width(sigma) Normalized by the engineering data CsI temp. （ 0 C) MeV/pC Light Yield : -1.3% / 0 C

Schedule Aug. Sep. Oct. Nov. Dec. Jan. Feb. FB assembling CB fabrication CB assembling Cosmic test/counter tuning Start data taking Evacuate system Unite three sectionsCheck Membrane Moving downstream Cosmic and evacuate test for the upstream A/D Card upgrade ADC Replacement BA and CC05 installation CV PMT install CC04/CC05 Fabrication CC04 Installation Cooling system for Barrel Additional Cabling Downstream vacuum test Middle section fabricationMembrane BCV Beam

Summary E391a is aiming at measuring the BR( K L    ) – Realizing Step-by-step Preparation of E391a – Three parts are being prepared in parallel – Manage to catch up the schedule Prompt start – Well tuned electronics and DAQ at the engineering run – Cosmic test for each detector components – Minimum beam time for tuning