Cell testing method
From Hall A Wiki
Revision as of 15:33, 21 December 2011 by Solvigno (Talk | contribs) (New page: 1) RTDs: - Test the target RTDs and the oven RTD at room temperature against a thermometer. - Record their offsets. - Discard RTDs with significant offsets. - Place se...)
1) RTDs:
- Test the target RTDs and the oven RTD at room temperature against a thermometer. - Record their offsets. - Discard RTDs with significant offsets. - Place selected RTDs on the cell.
2) Installation of the cell in the oven:
- Center the pumping chamber with respect to the oven windows. - Seal the oven with RTV. - Record position of the cell with respect to the pick-up coils for flux calculation purpose.
3) Laser alignment:
- Check laser alignment (and light loss) at each optical element. - Check 1/2 and 1/4 wave plates settings. - Check the spectrum analyzer for optimal absorption.
4) Cell testing:
- Set up the oven at the desired temperature. Wait for the temperature to stabilize. - Turn on the lasers. Wait for the temperature to stabilize. - Take NMR measurement every 3 hours. - When spin up is done, do the following tests: - EPR-NMR calibration: take EPR and NMR measurements 5 minutes apart following this sequence: EPR-NMR-EPR-NMR-EPR - temperature test: take NMR measurements with lasers on and off following this sequence: ON-OFF-ON-OFF-ON. Before each measurement, make sure the cell temperature is stable. - AFP loss test: take 5 NMR measurements 5 minutes apart.
5) Spin down:
- Turn off the laser and the oven. Wait for the temperature to stabilize. - Take NMR measurement every 3 hours.