===== Grand Raiden memo ===== ==== Preparation ==== === A/C === * Call OGFA sfatt (ext.: 8890) === 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 === * Setup and initialization for each experiment\\ http://www.rcnp.osaka-u.ac.jp/Divisions/np1-a/pukiwiki/index.php?Setting%20up%20the%20CAGRA%2BGR%20DAQ * Check if the daq can run or not by using pulser * Check if the disk space is enough or not ==== Tuning procedure ==== - Beam transportation - Beam transmission > 90% * BS3 - FCs at beam dump - Start up GR - Plastic scintillators - ADC raw 1d - TDC raw 1d - Correlation between ADC L & R - GR-GV is open or not? Push button sometimes. Looks OK. Hardware things. - Inside of GR chamber? D1-FC is blocking the beam? - Q1-FC is blocking the beam? - RF signals - Raw data is OK? - Channels assignment are OK? - Blocking stuff? - Installing the alminum plate - VDC wire check by continuum - Plastic scintillators HV optimization - VDC HV optimization - 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 - Optimization of beam energy resolution with the Au target (achromatic mode) - macro -- resmon? - GXTHC - GXCTH - GTHCTH - GX gate - See the histogram list in GR optics - The goal is 80 keV (FWHM) for proton 295 MeV - Au target has some excited states at low energy. This looks a child of the beam? - Changing the beam line setting takes time longer than 30 minutes (Nebiki-san & Furutaka-san) - 50 minutes on Dec. 5, 2017 by Nebiki-san & Furutaka-san - Optimization of beam energy resolution with the Au target (dispersion matching mode) - This optimization should be done after the tuning for achromatic mode - The goal is 20-30 keV (FWHM) with a target for proton 295 MeV (the best value is 14 keV (FWHM)) - The goal is 15 keV (FWHM) without a target for proton faint beam at 295 MeV - Change the GR angle from 8.5 degree to 0 degree - SC-FC is down - Faint beam - The beam is centered (0 mm) in GX - 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) - Y focus by changing the QM10 with Au target - Target Au --> blank - QM10UDD optimization - First UD-M table which can realize good Y focus should be made - UD (A) / M (A) / dE (keV) - 25.50 / -41.20 / 31 keV - 25.70 / -41.41 / keV - 25.90 / -41.41 / keV - 26.10 / -41.41 / keV - Q1-magnet focusing with the sieve slit and the carbon target - 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 * Q1-FC angle coverage: 0 - ~20 deg.