Background Rate Studies

This page summarizes various studies used to try to understand backgrounds produced in the detector from the 9 GeV coherent brem. beam that enters Hall D.

Simulation Information

A total of 10⁸ 9 GeV beam photons (1 second of beam time) were generated using the geometry and simulation current as of approx. December 1. Note that various hit thresholds exist for each detector system. Noise count rates are highly dependent on these thresholds.

CDC

Detector Configuration:

• Double-Hit Resolution: 250 ns
• Threshold: 1 keV
• Maximum Number of Hits (per Event): 100

The average background rate per straw in Hz as a function of ring number in the CDC.

A double-log plot of the energy of all hits in the CDC. The spectrum cuts off at 1 keV due to the GEANT threshold.

FDC

Detector Configuration:

• Double-Hit Resolution: 250 ns
• Threshold: 1 keV
• Strip Threshold: 5 mV (where is this applied?)
• Maximum Number of Hits (per Event): 100