<div dir="ltr">Hello everyone,<div><br></div><div>Thia and I put together the list of priorities and some details for the studies that we discussed during the meeting today. The date for beam to be restored is still very fluid but current estimates put it at the end of next week. We will keep you updated once we have more details.</div><div><br></div><div><span style="font-size:12.8000001907349px">Priority for studies:</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> 1. Harps, BPM and raster calibration, maybe beam energy study at the end (1 shift)</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> 2. GMp/DVCS combined optics studies of both spectrometers (2 days)</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> 3. Send beam through Compton chicane (1 shift)</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> 4. Compton and Moller polarimetry work interchangeably (3 days)</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> 5. SBS detector tests, can do during Compton polarimetry studies</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> 6. Ask for a second beam energy measurement**</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> 7. Check if accelerator can provide high intensity. If so then we can go </span><span style="font-size:12.8000001907349px">to Unser, BCM calibrations</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> 8. Another option if 6. is not possible is to ask for 5 pass for GMp measurement</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">**background for Compton has to be taken into account</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">Study details:</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - Optics studies:</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - requires 10-15 muA</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - Carbon, optics target, sieve, H elastics</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - HRS-R can stay at 52 degrees, but needs a new survey (which can be </span><span style="font-size:12.8000001907349px">done at the end of the run)</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - Compton studies:</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - go through chicane</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - test backgrounds</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - check new thick Si detector</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - beam size needs to be 0.1-0.2 mm (they have not provided smaller </span><span style="font-size:12.8000001907349px">than 0.5mm at high energy so far)</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - E locks on</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - Moller</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - tests needed to improve precision</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - with the current setup we should assign 2.5% systematic uncertainty</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - beam charge asymmetry with any whatever quality beam to synchronize </span><span style="font-size:12.8000001907349px">with HRS (~30 minutes)</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - needs BPMs, E locks</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - SBS tests:</span><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px"> - needs proton spectrometer and ECal at 20-30 degrees</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">Target:</span><br style="font-size:12.8000001907349px"><br style="font-size:12.8000001907349px"><span style="font-size:12.8000001907349px">The target will be He cooled to facilitate high currents on the optics targets. No target operator is required to be available for this condition. It will take ~2 shifts to liquify the H target, so must plan with target group in advance for day shift time to do this. Once there's a liquid H target, target operator shifts must be filled 24/7.</span></div><div><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px">Cheers,<br></span><div><div><div class="gmail_signature"><div dir="ltr">Ciprian <br><br>*************************************************<br>Ciprian Gal<br>Postdoctoral Researcher <br>University of Virginia, Va, USA<br>*************************************************<br></div></div></div>
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