12 10 2012 HRRL DetectorTests
Revision as of 19:51, 10 December 2012 by Foretony (talk | contribs) (→compare previous measurements & adjust threshold & Width)
RunPlan
BeamTune
Tune beam into zero line, max current, 10.5 MeV energy, 20 ns width, 300 Hz rep rate
For Reference, below is the the tune used on last day of July 2012 Positron run
https://wiki.iac.isu.edu/index.php/Beam_Test_Jul_27_2012#Tune
Measure Emittance
Ilyusha Background measurements
Previous Background tests during 2n correlation run
https://wiki.iac.isu.edu/index.php/2n_BKG_data
HV=1000 CFD = -12 mV
Previous run during neutron correlation experiment found 1 gamma/15 electron beam pulses
Tune beam into zero line, max current, 10.5 MeV energy, 20 ns width, 300 Hz rep rate
1.) Take a run with no shielding around Ilyusha
2.) Move Pb bricks around the scintillator to determine direction of background
3.) add shielding to accelerator
compare previous measurements & adjust threshold & Width
| Rate (gamma/pulse) | Beam COnfig (E,pulse width,peak current) | Configuration |
| 213/3746 = 1 /17 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 255 ns CFD output pulse width (this width was sued in the 2n correlation exp) |
| 213/2343 = 1/11 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 4 ns CFD output pulse width |
| 220/2374 = 1/11 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 100 ns CFD output pulse width |
| 53202/616 = nonsense | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 0 mV threshold on CFD, 4 ns CFD output pulse width |
| 794/862 = 1/1 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 2 mV threshold on CFD, 4 ns CFD output pulse width |
| 574/1213 = 1/2 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 4 mV threshold on CFD, 4 ns CFD output pulse width |
| 247/906 = 1/4 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 6 mV threshold on CFD, 4 ns CFD output pulse width |
| 662/3914 = 1/6 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 8 mV threshold on CFD, 4 ns CFD output pulse width |
| 201/1328 = 1/6.6 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 220/1580 = 1/7.2 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 14 mV threshold on CFD, 4 ns CFD output pulse width |
| 250/1176 = 1/5 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 4 ns CFD output pulse width |
| 252/937 = 1/4 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 221/917 = 1/4 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 4 ns CFD output pulse width |
| 239/634 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 8 mV threshold on CFD, 4 ns CFD output pulse width |
| 241/718 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 222/819 = 1/4 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 4 ns CFD output pulse width |
| 241/1011 = 1/4 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 14 mV threshold on CFD, 4 ns CFD output pulse width |
| 246/884 = 1/4 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 4 ns CFD output pulse width |
| 224/713 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 242/561 = 1/2 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 8 mV threshold on CFD, 4 ns CFD output pulse width |
| 269/550 = 1/2 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 6 mV threshold on CFD, 4 ns CFD output pulse width |
| 254/666 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 8 mV threshold on CFD, 4 ns CFD output pulse width |
| 250/755 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 233/775 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 4 ns CFD output pulse width |
| 205/754 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 14 mV threshold on CFD, 4 ns CFD output pulse width |
| 204/718 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 12 mV threshold on CFD, 4 ns CFD output pulse width |
| 214/760 = 1/3 | 10.5 MeV : 100 ns FWHM, 5.4 mA | UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 390/808 = 1/2 | 10.5 MeV : 100 ns FWHM, 3.2 mA | UNshielded illyusha scintilltor, 6 mV threshold on CFD, 4 ns CFD output pulse width |
beam current decreased from 5 to 3 mA during the measurements ; must measure beam current for each measurement.
Add 3 Pb Bricks to accelerator side
We discovered that a gate vavle was slowly closing due to a gas pressure problem. This explains why the rates were dropping above during the threshold tests.
| Rate (gamma/pulse) | Beam COnfig (E,pulse width,peak current) | Configuration |
| 51/3031 = 1/60 (.3 Hz) | 10.5 MeV : 100 ns FWHM, 6.8 mA, 20 Hz | 5" Pb in, UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 47/2307 = 1/50 | 10.5 MeV : 100 ns FWHM, 0 mA , RF on, 20 Hz | 5" Pb in, UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 70/3126 = 1/44 , 1/50 | 10.5 MeV : 100 ns FWHM, 6.8 mA , RF on, 20 Hz | 5" Pb out, UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 60/2728 = 1/45 (0.43) | 10.5 MeV : 100 ns FWHM, 0 mA , RF on, 20 Hz | 5" Pb out, UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 57/20728 = 1/363 (0.8 Hz) | 10.5 MeV : 100 ns FWHM, 6.8 mA , RF on, 300 Hz | 5" Pb out, UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
adding 5" of Pb between detector and accelerator decreased the rate from to 1/60 beam pulses
The cosmic + RF noise rate = 1/50 pulses
Increased PMT Voltage by 100 and decrease beam current
| Rate (gamma/pulse) | Beam COnfig (E,pulse width,peak current) | Configuration |
| 160/25837 = 1/161 (1.9 Hz) | 10.5 MeV : 100 ns FWHM, 1.68 mA , RF on, 300 Hz | 5" Pb out, UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
| 128/22979 = 1/180 (1.7 Hz) | 10.5 MeV : 100 ns FWHM, 0 mA , RF on, 300 Hz | 5" Pb out, UNshielded illyusha scintilltor, 10 mV threshold on CFD, 4 ns CFD output pulse width |
Electron/photon ratio
Compare magnet in and out using a scintillator at the exit window of the 90 degree line.