Development Period - February 9-10

Listed in order of suggested priority...

Re-measure emittance in order to analyze Run 1 conditions (3 hours)

• February 9, 2015:

• Identified parameters and details for a procedure
• Measured emittance and Twiss for 6.3 MeV/c setup
• Started emittance and Twiss for 5.5 MeV/c but harp is stuck so test deferred for now

Test hardware TOF veto at 31MHz (4 hours)

• Runs 8210 - 8217 with 0.225 um gold foil
• Example of VETO

Test background as a function of target ladder position on large target foil (0 hours)

• February 9, 2015:

• Deferred until re-doing emittance measurement at 5.5 MeV/c to try for smaller spot size with 5 or 10 mm rings too

Test Mott delayed operation (1 hour):

• Set of 6 runs while changing between No Delay and Delay=8
• Runs 8218 - 8223 with 1.0 um gold foil
• media:Delayed_Ana.pdf media:Delayed_Ana.pptx
• A dump of first 10000 events from Run 8218 media:Hel_8218_0.txt shows that S1 helicity is lacking FADC by 0 to a few events. FADC helicity is correct because it is read event by event in the same module at the same time.
• For the time being we will not run in delayed helicity mode because we cannot rely on S1. To use FADC helicity in delayed mode, decoder software development is required.

Test FADC time-of-flight readout and new Mott DAQ Configurations (2 hour)

• February 4, 2015:

• Added two more laser timing signals to FADC. From Disc 708, OUT signal was connected to FADC Ch10 and OUT_bar was connected to Ch12. The original laser timing signal is still connected to Ch9.

• Run 8224 with 1.0 um gold foil and Mott_SemiInt configuration (31 MHz beam) (unfortunately, FADC threshold for Ch10 and Ch12 was left at 100)
• Measure deadtime with 2.2 uA on 1 um gold foil:

• Run 8225: Mott_SemiInt configuration (FADC+TDC+Scalers), Deadtime = 28% at 5.1 kHz.
• Run 8227: SemiIntFast configuration (only readout of FADC, Blocklevel = 1) , Deadtime = 17% at 5.1 kHz.
• Run 8228: SemiIntBlock configuration (only readout of FADC, Blocklevel = 50) , Deadtime = 1% at 5.1 kHz.

• Mott DAQ Speed: media:Mott_DAQ_Improve_Feb2015.pdf media:Mott_DAQ_Improve_Feb2015.pptx
• Run 8235 with Thru Hole and Mott_SemiInt configuration (250 MHz beam). (FADC threshold for Ch10 and Ch12 is 1750)
• Meetin with DAQ Group Monday, February 16, 2015. Action items:

1. Haidong, with help from Bryan and Riad, will look at implementing a pedestal in X bins in front of NSB rather than at start of window to address using ~sine wave
2. Riad will need to turn laser sine wave into a pulsed wave so that there is a stable pedestal over at least X sample before rising edge
3. Alexandre will provide Joe a PR for VME64 crate and Joe will purchase one
4. Next access will need to get JLAB discriminator/scalars from tunnel
5. Alexandre and Riad will test JLAB disc/scalars, to look at using blocking mode for both FADC/Scalar
6. Once we can reliably use FADC timing we will eliminate the dependence on external TDC