PosRun 10 14 2013

Run list

Scaler channel #2 counts the number of beam pulses

Detector 4 is Beam Left and in ADC channel 7, Ortec Dual Spec amp set to course=10, fine=39, Canberra CFD set to 85 mV lower threshold

Detector 1 is Beam Right and in ADC channel 3, Ortec Dual Spec amp set to course=20, fine=10, Canberra CFD set to 70 mV lower threshold

In-flight

Run #	Run Duration (s)	Configuration
6488	min s	2->60Hz rep rate, Looking at NaI in shielded cell at -600 Volts, Magnet on Accelerator side deflects electrons, Tungsten target is out, triggering only on the beam gate and looking at ADC channel 3
6489	min s	same as above except: 120Hz rep rate, -500 Volts,
6490	min s	same as above except: -550 Volts,
6491	min s	same as above except: -575 Volts,
6492	min s	same as above except: inserted Aluminum brick to be sure electrons are staying on accelerator side, drops NaI output by factor of 2
6493	min s	same as above except: -600 Volts
6494	min s	same as above except: -700 Volts
6498	min s	same as above except: -500 Volts, magnet out
6499	min s	same as above except: -700 Volts, very similar ADC spectrum for magnet in
6500	min s (54420 , 120 Hz pulses =453.5 sec)	same as above except: removed Al brick beam stop, increased current from zero until signal was observed in experimental cell NaI (probably mostly dark current from RF cavity)
6501	min s (54297 pulses)	same as above except: inserted Al brick beam stop,
6502	min s (54297 pulses)	same as above except: REmoved Al brick beam stop

FC -vs- 90A beam stop correlation

FC = Aluminum brick 2" from exit window near NaI detectors

50 Ohm scope termination

90 A BS (nVs)	FC (nVs)
47	25
24	11.9
13	6
6.1	2.3
4.8	1.8

Positrons_Using_40Mev_Linac