Difference between revisions of "Spectrometer Optics 2pass"

Latest revision as of 19:41, 29 April 2015

Procedure without Sieve-slit

• Time estimate: 2 hours

* Take a run at the following kinematics without the sieve-slit collimator.
* 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.
* Electron rates assume 5 carbon foils, 5 mSr acceptance, and 8% 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.

We want to take runs with the following Q1 currents:

1. 0%: 159.75 A
2. -6%: 150.165 A
3. -5%: 151.7625 A
4. -4%: 153.36 A
5. -3%: 154.9575 A
μA
6. +5%: 167.7375 A

Procedure with Sieve-slit

• Time estimate: 34 hours

* Trained personnel will be required to install the 1-inch tungsten 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 8% delta acceptance.

We want to take a full statistics run at a Q1 current setting -5%(151.7625 A).

We want to take short runs with the following Q1 currents:

1. +5%: 167.7375 A
2. Off: 0 A

Delta Scan with Proton 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.

For each ΔP (%) setting, we want to take 3 runs with different Q1 currents:

For ΔP = -4%, we want the following Q1 currents:

1. -5%: 229.4649 A
2. +5%: 253.6191 A
3. TBD

For ΔP = -2%, we want the following Q1 currents:

1. -5%: 225.0132 A
2. +5%: 248.6988 A
3. TBD

For ΔP = 0%, we want the following Q1 currents:

1. -5%: 220.76385 A
2. +5%: 244.00215 A
3. TBD

For ΔP = +2%, we want the following Q1 currents:

1. -5%: 216.31215 A
2. +5%: 239.08185 A
3. TBD

For ΔP = +4%, we want the following Q1 currents:

1. -5%: 211.86045 A
2. +5%: 234.16155 A
3. TBD

Hall A Gmp Luminosity Scan

Set Left HRS to P = 1.0 GeV, θ= 25, 2mmx2mm raster. Take 10 minute runs with the targets and beam currents listed below. Set prescale factor to keep livetimes approximately constant for each current with a given target.