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

40 MeV electrons are hitting the positron production Tungsten target

Run #	Run Duration (s)	Configuration
6503	3 min 46 s ( pulses)	Dipoles in positron mode. Al Brick in along 8 inch length
6504	min s ( pulses)	same as previous run, Al brick OUT
6505	min s ( pulses)	same as previous run, Dipoles in Electron mode,
6506	min s ( pulses)	same as previous run, Selection Magnet bending electrons up positioned after 50 micron Ti vacuum window,
6507	min s ( pulses)	same as previous run, dipoles set to positron mode and selection magnet rotated 180 degrees so positrons bend up,
6508	min s ( pulses)	same as previous run:increase voltage from -700 to -850
6509	min s ( pulses)	same as previous run, installed 2" thick graphite hardener
6510	min s ( pulses)	same as previous run, removed graphite hardener and selection magnet, returned to dipoles in electron mode,

reconfigure with sweep magnet in shielded cell to deflect charged particles towards NaI detector #3,

6511	min s ( pulses)	dipoles in electron mode transporting 8 MeV, NaI at -700 Volts
6512	min s ( pulses)	dipoles in electron mode transporting 6 MeV, Magnet is OUT
6513	min s ( pulses)	dipoles in electron mode transporting 6 MeV, Magnet is IN and deflecting positrons towards NaI
6514	12 min 3 s ( pulses)	same as last run except: dipoles in positron mode, doubled current from last run
6515	min s ( pulses)	same as last run except: positron dipoles set to 8 MeV, increased current and rep rate (150 Hz)
6516	min s ( pulses)	same as last run except: positron dipoles set to 6 MeV,
6517	2 min 18 s ( pulses)	same as last run except: Magnet is out
6518	7 min 10s ( pulses)	same as last run except: positron dipoles set to 8 MeV, sweep Magnet is out
6519	min s ( pulses)	same as last run except: sweep Magnet is In positron bending mode
6520	min s ( pulses)	same as last run except: sweep Magnet is In electron bending mode
6521	min s ( pulses)	same as last run except: dipoles set to electron mode

38 MeV electrons with 859 pVs/50 Ohms per 100 nsec wide pulse

a scope measurement of the 38 MeV electron pulse impinging the tungsten target suggested that one pulse had

electrons

or given the 100 nsec pulse width the peak current is

= 0.017 Amps

I believe we need to run at 0.01 Amps to keep the ion pumps working.

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

50 Ohm scope termination