HRS Checkout (Experts)

The detector checkout is best done using a fairly uniform illumination, which is provided for by 20 μA on the central Carbon target at the following kinematics:

E' = 3.056 GeV, θ = 19 degrees (W² = 2.53 GeV, Q² = 2.43 GeV²). The HRS electron rates should be about 270 Hz.

Ebeam [GeV]	P0 [GeV/c]	θe [deg]	Collimator	Target	Fast Raster X x Y	Beam Current	Trigger
7.3	3.056	19.0	None	Single Carbon	off	20 μA	S0&&S2m

1. With the above kinematics, take a run (at least 100K events or 10 minutes) and verify that all detector channels are working.
2. Using the same run, produce a ROOT tree, and do the following: make a spectrum of x vs. y at the focal plane. What you should see is a "spider" with 5 legs. The non-straightness of the central legs indicates there is an offset in the Z or Y direction. If you don't see a "spider" or something resembling it, then of of the polarities of the HRS magnets is set wrong (or a magnet is off).
3. Check that the signals are well timed.
4. Determine correct thresholds.
5. Verify all scalers are incrementing.
6. Check for double pulsing and time the wire chamber signals.
7. Are the scintillator signals for on scale in the scintillator ADCs?
8. PID threshold checks.