Difference between revisions of "Spectrometer Optics"

Revision as of 15:13, 10 February 2015

Procedure without Sieve-slit

• Time estimate: 4 hours

* Take a run at the following kinematics without the sieve-slit collimator on the multi-foil carbon target.
* Start with initial right HRS spectrometer tune with the SOS quad in place of right Q1.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Rates assume 5 carbon foils, 6 mSr acceptance, and 9% delta acceptance.
* A GMp expert will check the data quality and decide, if the right HRS tune needs to be adjusted to change the size of the acceptance.
* This process will be repeated until the spectrometer tune is satisfactory.

Procedure with Sieve-slit

• Time estimate: 1-2 hours

* Trained personnel will be required to install the 1-inch lead sieve-slit collimator onto the front face of the HRS.
* Take a sieve slit run with the multi-foil carbon target for the inelastic kinematics in the table.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Repeat the above with the beam position shifted so that you see a vertical shift by one row.
* Rates assume 5 carbon foils, only 25 out of 63 sieve holes have events (~ 0.265 mSr acceptance), and 9% delta acceptance.
* Note: if the right HRS minimum angle is 35 degrees instead of 33 degrees, then the rate will be ~ 50 Hz instead.

Delta Scan with Hydrogen Elastic

• Time estimate: 2-3 hours

* Trained personnel will be required to remove the 1-inch lead sieve-slit collimator onto the front face of the HRS.
* Take a run with the 15 cm liquid hydrogen target for the elastic kinematics in the table.
* There will be a time lapse between settings until the right dipole reaches the desired momentum and is stable.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.

Elastic from Hydrogen

• Time estimate: 1-2 hours

* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Elastic electron-proton measurement.  Assuming a 15 cm LH2 target, a spectrometer acceptance of 5 msr and elastic from Eric's rate program 

  to compute the cross-section.