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Plan for FPP commissioning with polarized beam
  1. Do measurement of proton polarization transfer in elastic ep scattering at Q2 = 0.8 at beam energy of 1.645 GeV. Estimated time of measurement is 2 hours. See fpp_pol_1 in following pages for details.

  2. Move hadron spectrometer to 48.99° and measure proton polarization transfer in elastic ep scattering at Q2 = 0.8 at beam energy of 1.645 GeV. Estimated time of measurement is 2 hours. See fpp_pol_2 in following pages for details.

  3. Move hadron spectrometer by 45.99° and measure proton polarization transfer in elastic ep scattering at Q2 = 0.8 at beam energy of 1.645 GeV. Estimated time of measurement is 2 hours. See fpp_pol_3 in following pages for details.

  4. Do measurement of proton polarization transfer in elastic ep scattering at Q2 = 0.65 at beam energy of 1.645 GeV. Estimated time of measurement is 1 hours. Assume 1 hour to set magnets and do angle change. See fpp_pol_4 in following pages for details.

Settings for fpp_pol_1
Beam Energy
1.645 GeV

Beam position
< .25 for x and y for 3A and 3B

Raster size
1.5x1.5mm

Beam Current
6-12mA. Set current to give maximum data rate with deadtime < 60%.

Target
15cm LH2

Spectrometer settings
Spectrometer Momentum Angle Collimator
Electron 1.219 GeV 36.82° 6msr
Proton .9908 GeV 47.49° 6msr

Magnet settings
Spectrometer Dipole Q1 Q2 Q3
Electron 0.479646 T 911.840 A 521.888 A 482.527 A
Proton 0.365674 T 740.965 A 424.089 A 392.104 A

The electron quads are all set to negative polarity. The hadron Q1 and Q3 are set to positive polarity, but Q2 is set to negative polarity.

Data taking
The T5 prescale should be one. The prescales for T1,T2,T3 and T4 should be set to give less than 5 Hz trigger rate for each. The T8 prescale should be set to maximum.

The trigger setup should be proton_875-1170.settings .

The goal is about 8.6x106 hydrogen elastic events. If a data rate of 1200 Hz is obtained, then this should take 2 hours.

Settings for fpp_pol_2
Beam Energy
1.645 GeV

Beam position
< .25 for x and y for 3A and 3B

Raster size
1.5x1.5mm

Beam Current
6-12mA. Set current to give maximum data rate with deadtime < 60%.

Target
15cm LH2

Spectrometer settings
Spectrometer Momentum Angle Collimator
Electron 1.219 GeV 36.82° 6msr
Proton .9908 GeV 48.99° 6msr

Magnet settings
Spectrometer Dipole Q1 Q2 Q3
Electron 0.479646 T 911.840 A 521.888 A 482.527 A
Proton 0.365674 T 740.965 A 424.089 A 392.104 A

The electron quads are all set to negative polarity. The hadron Q1 and Q3 are set to positive polarity, but Q2 is set to negative polarity.

Data taking
The T5 prescale should be one. The prescales for T1,T2,T3 and T4 should be set to give less than 5 Hz trigger rate for each. The T8 prescale should be set to maximum.

The trigger setup should be proton_875-1170.settings .

The goal is about 8.6x106 hydrogen elastic events. If a data rate of 1200 Hz is obtained, then this should take 2 hours.

Settings for fpp_pol_3
Beam Energy
1.645 GeV

Beam position
< .25 for x and y for 3A and 3B

Raster size
1.5x1.5mm

Beam Current
6-12mA. Set current to give maximum data rate with deadtime < 60%.

Target
15cm LH2

Spectrometer settings
Spectrometer Momentum Angle Collimator
Electron 1.219 GeV 36.82° 6msr
Proton .9908 GeV 45.99° 6msr

Magnet settings
Spectrometer Dipole Q1 Q2 Q3
Electron 0.479646 T 911.840 A 521.888 A 482.527 A
Proton 0.365674 T 740.965 A 424.089 A 392.104 A

The electron quads are all set to negative polarity. The hadron Q1 and Q3 are set to positive polarity, but Q2 is set to negative polarity.

Data taking
The T5 prescale should be one. The prescales for T1,T2,T3 and T4 should be set to give less than 5 Hz trigger rate for each. The T8 prescale should be set to maximum.

The trigger setup should be proton_875-1170.settings .

The goal is about 8.6x106 hydrogen elastic events. If a data rate of 1200 Hz is obtained, then this should take 2 hours.

Settings for fpp_pol_4
Beam Energy
1.645 GeV

Beam position
< .25 for x and y for 3A and 3B

Raster size
1.5x1.5mm

Beam Current
6-12mA. Set current to give maximum data rate with deadtime < 60%.

Target
15cm LH2

Spectrometer settings
Spectrometer Momentum Angle Collimator
Electron 1.299 GeV 32.02° 6msr
Proton .8775 GeV 51.692° 6msr

Magnet settings
Spectrometer Dipole Q1 Q2 Q3
Electron 0.511106 T 971.648 A 556.119 A 514.176 A
Proton 0.323843 T 656.203 A 375.575 A 347.249 A

The electron quads are all set to negative polarity. The hadron Q1 and Q3 are set to positive polarity, but Q2 is set to negative polarity.

Data taking
The T5 prescale should be one. The prescales for T1,T2,T3 and T4 should be set to give less than 5 Hz trigger rate for each. The T8 prescale should be set to maximum.

The trigger setup should be proton_875-1170.settings .

The goal is about 8.6x106 hydrogen elastic events. If a data rate of 1200 Hz is obtained, then this should take 2 hours.

File translated from TEX by TTH, version 0.9.