Summary Winter 2024 Run

RC Summary, March 2024 Test Run (A. Deur)

The March 2024 test run took place from March 11 to March 15. Its objective was to test the GEM-TRD detector, along with other GEM detectors, and to checkout the beam line following a year of downtime. The test proved to be very successful. Detailed information for the run are provided on the run page.

Beam was scheduled to arrive March 11 (Monday) afternoon, but usable beam (for this test; not requiring photon polarization) became available on March 12 around 5:20 am. Beamline and beam quality checks were performed without any major issues. The biggest problem was that the motor driving the amorphous radiator ladder and our harp was poorly responding. It was not a showstopper and was fixed opportunistically during a downtime. (It just needed lubrication). Photon beam transmission to the hall was adequate, with a rate of about 5 kHz in the PSC counters compared to the expected 8.7 kHz for optimal, converging beam (100 nA, 2×10^-5 Al radiator, 750 μm TPOL converter). Testing and optimization of the GEM-TRD started, with Ar gas in the detector.

On March 13th, accelerator maintenance took place from 7 am to 9 pm, with Hall D beam resuming only on the 14th at 1:30 am. During this downtime, the gas was changed from Ar to Kr. Testing of the GEM-TRD proceeded smoothly, with many Rapid Accesses for Transition Radiator configuration changes. Initially, it was planned that the Hall D beam would be terminated on the 15th (Friday) at 7 am. However, delays in the readiness of Hall B (which beam we were using) allowed us to run longer, up to mid-Saturday if needed. However, by the end of Friday, our program was completed, and we asked MCC to terminate the beam. The radiator was retracted, and the collimator was put in blocking position. The PS and sweeping magnets were ramped down, and the Hall along with the tagger were set into "Power Permit" mode for the weekend.

In all, we had 88h scheduled, were up for 53.5h, got 50h of ABU and 9.8h of BANU.