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hv_bias

Detector bias control

HV Remote control

The high-voltage of the plastic scintillator and the MCP at Object, the TPPACs at Intermediate Image, the CRDCs, ion chamber, plastic scintillator, and hodoscope at Focal Plane are remotely controlled via CS-Studio Phoebus (see figure below).

CS-Studio Phoebus DIAG HV control

This “S800 HV Bias Power Supply” page is linked from both “S800” and “DIAG” launchers, a screenshot of the former of which is shown below.

The ramp rate can be changed in the “Details”. ISEG cards that are used here have only one ramp rate per bank of channels, so changing the rate for one channels will change the rate for all the others in the same bank. When you ramp the HV, ensure that the ramp rate is set properly.

Each channel can also be accessed from by going to “FRIB EXP” → “Power Supplies” and open the “EXP-S3” tab, which looks like the screenshot below.

CS-Studio Phoebus PS HV control

The actual HV modules are located on the top level of the S3 vault, under the FP chamber.

Other examples of HV values used with different fragment beams are:

* CRDC1 and CRDC2:

  • For He-3 @ ~130 MeV/u: CRDC1 (Anode=1120 V, Drift=1000 V); CRDC2 (Anode=1120 V; Drift=1000 V)
  • For Be-12 @ ~30 MeV/u: CRDC1 (Anode=970 V, Drift=1000 V); CRDC2 (Anode=970 V; Drift=1000 V)
  • For Ar-34 @ ~80 MeV/u: CRDC1 (Anode=860 V, Drift=1000 V); CRDC2 (Anode=840 V; Drift=1000 V)
  • For Zn-58 @ ~44 MeV/u: CRDC1 (Anode=740 V, Drift=1000 V); CRDC2 (Anode=740 V; Drift=1000 V)
  • For Rb-74 @ ~40 MeV/u: CRDC1 (Anode=650 V, Drift=1000 V); CRDC2 (Anode=650 V; Drift=1000 V)
  • For U-238 (88+) @ ~70 MeV/u: CRDC1 (Anode=570 V, Drift=1000 V); CRDC2 (Anode=570 V; Drift=1000 V)

* FP scintillator (E1 up and E1 down):

  • For He-3 @ ~130 MeV/u: UP (1790 V); DOWN (1760 V)
  • For Be-12 @ ~30 MeV/u: UP (1770 V); DOWN (1700 V)
  • For Ar-34 @ ~80 MeV/u: UP (1580 V); DOWN (1510 V)
  • For Zn-58 @ ~44 MeV/u: UP (1400 V); DOWN (1340 V)
  • For U-238 (88+) @ ~70 MeV/u: UP (1180 V); DOWN (1280 V)

* IC:

  • Typically 200 V
hv_bias.txt · Last modified: 2023/10/17 09:40 by noji