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Grand Raiden memo

Preparation

VDCs

  • Check if gas is flowing or not
  • Check if the preamps are turned on or not
  • Check if the fans are turned on or not
  • The threshold of VDC HV supply is 40 uA for the proton beam at 300 MeV at E483 and E377+E422
  • The GR VDC threshold 4 uA –> 20 uA (sometimes 40 uA is used for 0 deg. exp.)

Viewers

  • Check if the viewers can move correctly or not
    • Target viewer
    • Q1-FC viewer
    • FPS viewer
    • 0-deg. dump viwer
    • 0-deg. Tami-Q viwer

Cameras

  • Check the image from the console
    • Target viewer
    • Q1-FC viewer
    • FPS viewer
    • 0-deg. dump viwer
    • 0-deg. Tami-Q viwer

FCs

  • Check if the FCs have a correct connection or not by tester
  • Check if the FCs have a correct isolation or not by 1000V insulation tester
    • Q1-FC
    • FC at 0-deg. dump
    • FC at FPS
  • Check if the FC is connected to current integrator

Vacuum chambers and valves

  • Check if all chambers do not have leak or not
    • The pressure should be less than about 1*10^-2 Pa
  • Check if all gate valves are open or not

Targets

  • Check if target ladder can move correctly or not

Plastic scintillators at GR FP

  • Check if the signals are OK or not by oscilloscope
    • The model of PMTs is H7195. The voltage limit is -2700V.

Magnets

  • Check if all magnets can be excited or not

Detectors

  • Energy calibrations

Log book

  • The log book should be prepared during beam tuning

DAQ

Tuning procedure

  1. Beam transportation
  2. Beam transmission > 90%
    • BS3 - FCs at beam dump
  3. Start up GR
    1. Plastic scintillators
      1. ADC raw 1d
      2. TDC raw 1d
      3. Correlation between ADC L & R
      4. GR-GV is open or not? Push button sometimes. Looks OK. Hardware things.
      5. Inside of GR chamber? D1-FC is blocking the beam?
      6. Q1-FC is blocking the beam?
    2. RF signals
      1. Raw data is OK?
      2. Channels assignment are OK?
    3. Blocking stuff?
    4. Installing the alminum plate
    5. VDC wire check by continuum
    6. Plastic scintillators HV optimization
    7. VDC HV optimization
    8. Energy calibration by the C target
      • Check if the nuclide of the primary beam is correct or not
      • Coefficient for MeV/mm
      • By the way, SH5 is a momentum slit
    9. Optimization of beam energy resolution with the Au target (achromatic mode)
      1. macro – resmon?
      2. GXTHC
      3. GXCTH
      4. GTHCTH
      5. GX gate
      6. See the histogram list in GR optics
      7. The goal is 80 keV (FWHM) for proton 295 MeV
      8. Au target has some excited states at low energy. This looks a child of the beam?
    10. Changing the beam line setting takes time longer than 30 minutes (Nebiki-san & Furutaka-san)
      1. 50 minutes on Dec. 5, 2017 by Nebiki-san & Furutaka-san
    11. Optimization of beam energy resolution with the Au target (dispersion matching mode)
      1. This optimization should be done after the tuning for achromatic mode
      2. The goal is 20-30 keV (FWHM) with a target for proton 295 MeV (the best value is 14 keV (FWHM))
      3. The goal is 15 keV (FWHM) without a target for proton faint beam at 295 MeV
      4. Change the GR angle from 8.5 degree to 0 degree
      5. SC-FC is down
      6. Faint beam
      7. The beam is centered (0 mm) in GX
      8. Check the resolution (30 keV (FWHM) at GX of 0 mm, 25 keV (FWHM) at GX of -400 mm at E377 and E422 on Dec. 5, 2017)
      9. Y focus by changing the QM10 with Au target
      10. Target Au –> blank
      11. QM10UDD optimization - First UD-M table which can realize good Y focus should be made
        1. UD (A) / M (A) / dE (keV)
        2. 25.50 / -41.20 / 31 keV
        3. 25.70 / -41.41 / keV
        4. 25.90 / -41.41 / keV
        5. 26.10 / -41.41 / keV
  1. Q1-magnet focusing with the sieve slit and the carbon target
  2. Q1-magnet defocus with the sieve slit and the carbon target

Restrictions

  • p 400 MeV - 10 nA (better less few nA) at SC-FC
  • p 300 MeV - 20 nA at SC-FC
  • 3He 420 MeV - 10 pnA at D1-FC (maybe too high)

E404

  • Beam transportation
  • Transmission check
  • HV and threshold tuning of plastics
  • HV tuning of VDCs

After experiments

  • If no one (magnet at N0 nor EN?) is using the power of the magnets, we can turn off the main switch of the power.
  • We do not have to stop the cooling water.

Modes

  • 0-deg. DSR+ mode
  • 0-deg. (p, p') dump mode
  • 0-deg. (alpha, alpha') mode

Beam time

  • 1.5-2 days for a single target and a single angle setting
  • 1 week for polarized beam for a single target and a single angle setting

Dispersion matching

  • Changing beam line setting from achromatic mode: 1 - 2 hours
  • Dispersion matching tuning : 6 hours
  • In total 9 hours or something
  • The Q magnet of the WS magnet should not be changed for the dispersion matching
  • The horizontal size of the beam spot at the target can not be narrow

Resolutions

  • Achromatic mode
    • p 295 MeV : 60-100 keV (FWHM)
    • p 392 MeV : 80 keV (FWHM), best resolution
    • 12C 1200 MeV : 240 - 400 keV (FWHM)

For 12C beam at 250 MeV (E404, Tsumura-san's exp)

  • VDCs
    • HV (initial values): CATH: -4.55kV, POT: -0.30 kV
    • HV (optimized values): CATH: -4.40kV, POT: -0.35 kV

GR DAQ

* The web controller is a set of a server side and client side programs

  • If you change the program, we have to restart the web browser in order to erase the cash in the browser

* vmeserver:8080 –> Tomcat server is working

  • Account: quser
  • Password: please ask me

Memos

  • Always flow the cooling water on the magnets of GR and LAS
  • Keep the GR and LAS chambers vacuum
  • isobutane is used also by EN (but GR- and LAS-VDCs are the main users)
  • Right-hand system for GR and LAS
research/memos/gr/gr_memo.1542764592.txt.gz · 最終更新: 2018/11/21 10:43 by kobayash
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