1. Who am I? ● Daniel John Kirby ● Carnegie Mellon Physics Class of 2013 ● In Hall A June-July 2012

2. Task: Implement systems to make FASTBUS readout faster (using CODA)

3. The Goal: Reducing Deadtime Main Sources of Deadtime Conversion Readout

4. Mathematical Model

5. Tasks to Implement Multiblock Readout SFI sequencing Event Blocking and Parallel Buffering Module Buffering Sparsification Library Implementation

6. Sparsification

7. Event Blocking Illustrated Thanks to Dave Abbott for this idea.

8. Increasing the Buffer Depth

9. Parallel Buffering Split TDC buffer into two distinct buffers. Readout and trigger acceptance can happen concurrently

10. Sequential vs. Parallel Buffering

11. Looking Forward: Parallel Module Buffering Reduces effective trigger rate. Thanks to Igor Rachek for original concept. Thanks to Bryan Moffit for help improving this diagram.

12. Effect of Module Buffering

13. Acknowledgements Once again I'd like to extend special thanks to: Bogdan Wojtsekhowski Bryan Moffit Dave Abbott Igor Rachek

14. Magnetic Field in Gas Cherenkov Counter By: Austin Milby, Menchville High School, class 2013 Physics is COOL!

15. Magnetic Field in Gas Cherenkov Counter Introduction WHAT: Shielding of PMT’s from magnetic field generated by BigBite WHY: Magnetic field can cause electrons in PMT to change direction and bend away from dynodes, resulting in skewed data HOW: By implementing a magnetic shielding box for use in the Cherenkov Counter, we can reduce the presence of the magnetic field around the PMT’s which will result in more accurate data Study done by SLAC found that Y-orientation of PMT is most severely affected by magnetic field. Need field to be bellow 1 Gauss!

16. Detector of the BigBite spectrometer in A1n experiment I am working with magnetic shielding of the PMT for the Gas Cherenkov counter

17. BigBite magnet and the field components Field components are of 5-10 Gauss At PMT the field need to be reduced to the level of 0.5-1 Gauss Bz component, Gauss By component, Gauss Bx component, Gauss -100cm 100cm 7 2 -2 10 5 1 -2.5 -4 (through center of Cherenkov Counter)

18. The layout of the PMTs in the counters Design of Magnetic Shielding Box being considered for use in detector. It will be placed in green area on picture. Mirror PMT face Center of counter where data on previous slide was obtained

19. BigBite Magnet and the Field Components (2) (Data taken along purple line) Bx component, Gauss By component, Gauss Bz component, Gauss (Along surface of PMTs) 100cm -100cm

20. Magnetic Shielding Black box outlines location of PMTs in shielding box. PMT faces NOTE: Data taken with external field of 20 Gauss and current in compensation coil set at 120 amps