Hall A Run Coordinator Report

N→ΔSRC commissioning

Juliette MammeiMarch 8, 2011

N→Δ

14 kinematic settings7 days

Could we do it?

Would the evil RHRS foil our plans?How long would it take to beat down the deadtime?

How many CODA dragons would have to be slain?

Challenges

Many kinematic settings, with background and optics runs at each… and a late start.

• Deadtime• Signal-to-noise• RHRS• CODA/DAQ setup

The Run Plan15 μA for #1, #225 μA for #3

80 μA for #7, #540 μA for #6

Remaining settings:

Used 4cm target for #11, #12 with 55 μA and 80 μA, respectively80 μA, 4cm / 40 μA, 15 cm for #8

30 μA, 15 cm for #9, 50 μA for #1035 μA, 15 cm for #13 and #14

Deadtime…• ROC 10 was configured incorrectly– Bob and Alex changed bb_sfi3.crl so that it has a flag

"onlytriglatch“ and set it =0; we decided to run buffered instead

• To BUF or not to BUF, that is the question...– Use BUF, not Buffered in the configuration file

Signal to Noise

Setting #7 had a much better signal to background than #6

RHRS• Bad spectrometer! Bad! You should go the way we tell you to

go…- AND - • Don’t lie to your shift leader…

When we first tried to move the RHRS, it refused. Howard and Jack worked it over (I mean worked on it) and it eventually moved.

Still reports the wrong direction, though it will move now(positive means away from the beamline)

CODA issues• Issues with different configurations changing– buffered vs. unbuffered– Taking different ROCs out of readout, etc.

• Run numbers not incremented– Happened twice– Not correlated with anything yet

N→Δ Experiment Summary• Nearly completed 13 out of 14 kinematic settings– Reduced charge for settings #9 and #13, skip #4– 94% of the data in ~100% of the time

• This was a new experience for me – it was very exciting with all the spectrometer changes and it required an intense effort by many people – Special thanks to Ran, Or, Larry, Vince, Alex and Bob!

SRC commissioning• Got some LD2 data before target warm-up– Neutron detection efficiency 36% (either unbelievably good or

just unbelievable – probably ~25%)– 800 neutrons/hour (expecting 100 neutrons/hour)

• Target work ongoing– Hope to pump down overnight in case Hall C can’t cool down

on Wednesday, we want to be ready• Some DAQ work for SRC going on in Hall• Parasitic ADC channel repairs and put in Čerenkov in LHRS• Rates on carbon seemed too low…

SRC commissioning

HAND TOFscale is ns, but there is an offset and width not fully calibrated

Pending issues

• CODA not incrementing runs (happened twice)• Target work is ongoing• Target cooldown? (waiting for final word from Hall C)• RHRS reports CCW when it goes CW (and vice-versa)• DAQ configuration being worked out