1. BigBite Hadron Detector Status Hall A Collaboration Meeting Xiaohui Zhan On behalf of the E05-102 collaboration MIT Jun 21, 2007

2. BigBite Hadron Package: First used in SRC experiment: consists of an auxiliary plane and a trigger plane. Now the frame is under modification(Glasgow): for both threshold pi and 3He(e,ed) experiments.

3. Goal : excellent discrimination between deuteron, proton, and unresolved kaon and pion at low momentum region. E dE

4. 1. Remove upper longitudinal beams2. Remove bottom beams3. Lower the slanted support beams New Frame SRC Frame 5. Remove auxiliary plane, reuse the beams in step 2 to construct the base 6. Add 4 new longitudinal beams 4. Add cross steal beams to mount the wire chamber 7. Add brackets to mount the shielding

5. Modification Inventory: 1.100x100 Al EXTRUSION MA1-5-02-02/1050 x4 2.T BOLTS M8 A35-60 x20 3.T BOLTS M8 A35-20 x12 4.MOUNTING BRACKET A30-40 x16 5.MOUNTING BRACKET A30-00 x4 6.DOUBLE EXTRUSION NUT x12 7.UNIVERSAL CONNECTOR WITH BASE 50 A20-90 x12 Note: additional 4 pieces are added as support when the frame is tilted backward, so that we can lift the wire chambers straight up. Two steel bins which are used to hold the back wire chamber will be made by Jlab machine shop.

6. E-E Trigger plane Consist of 24 scintillator bars Dimension: 500x86x3 mm 3 ( E) 500x86x30 mm 3 (E) PMT test was done: higher HV was applied compared to SRC experiment 56 PMTs have bad connection from light guide, they were taken off and being fixed… Electronics Schematic Design (Bryan Moffit): PMT signal flow diagram. Rack setup and cable map VDC read out not ready, but will be the same as that being used for the electron package.

7. Thanks to Glasgow technician group working on the frame modification: We will be ready for the full package test when the updated wire chamber arrives!