1. Group Meeting 2004/07/08
Jia-Ye Chen

2. Contents SDLT 320 Autoloader (MTX) TPC (part1)
Improvement of the Wire Gain Near the Frame of a TPC

3. SDLT 320 Autoloader (MTX)
SDLT had installed on the “hepfs” fileserver completely.
To install the remote control software, MTX, and it could work now. Only “SuperUser” could execute the MTX program.
Waiting for reboot the host-computer (hepfs fileserver) to initialize the Sequential-Access mode.
A simple “MTX User Guides” was finished.

4. Time Projection Chamber
Basic elements of a TPC

5. Schematics of the drift and detection process of charges on the wires of the TPC end-plate

6. Schematic arrangement of a wire chamber

7. Electric field lines in a cell of a MWPC for a TPC

8. Electric field lines with the gate in “open state” and in “closed state”

9. Different modes for gating the TPC

10. Improvement of the Wire Gain Near the Frame of a Time Projection Chamber
In wire chamber the gain usually drops to zero near the frame.
The gain loss close to the frames which hold sense and field wires is caused by modification of the E field: due to the dielectric constant ε of the glassfiber epoxy frame and the glue, the density of the electric field lines is reduced close to the sense wires edges.
The aim of the test was to find a voltage combination on the guards that could recover the gain keeping safe chamber operation.

11. Section of the Frame

12. Results of the test with both guard rings