[BTeam] large radiation readings during 980 setup

[Jay Benesch]

In the few minutes since I first read this I haven't come up with 
anything actionable, which is why I didn't send it to mcc_ops.

https://logbooks.jlab.org/entry/3896176  by Pavel Degtiarenko

The 7A15 detector is operational, further troubleshooting is not needed. 
All NDX detectors are live and produce signals now. Few photon channels 
are noisier than others, not critical for the neutron measurements in 
normal conditions.
Illustrations to the beam losses during beam recovery are shown in the 
attachments. Observed signals at 1L08, 1S01, and 7A15.
The beam first produced spiked dose rates at 1L08, at the levels ~550 
R/h photons, ~90 rem/h neutrons.
Then for about 10 min intermittent dose rates at 1S01 at levels ~30 R/h 
photons, ~20 rem/h neutrons.
Then a single spike at 1S01 at the level of ~230 R/h photons, ~70 rem/h 
neutrons.
Then there was a photon flash at 7A15 at 20:49:05, very short, even not 
registered in the beam current PV, at the level of about 1 kR/h photons, 
and no neutrons. The currents in the photon and neutron ICs were about 
the same, and their weighted difference was corresponding to -1 rem/h 
neutrons, meaning that there was no neutrons during that flash. The 
illustration to the limitations of the method: can't measure neutrons if 
their dose rate level is about or below ~1/1000 of that of photons'.
Then at 21:04:45 there was a "normal" beam loss around the Arc 7A15, 
with the dose rates about 16 R/h photons, and 11 rem/h neutrons, for a 
couple minutes.

http://devweb.acc.jlab.org/CSUEApps/atlis/view_attachment.php?attachment_id=14980

http://devweb.acc.jlab.org/CSUEApps/atlis/view_attachment.php?attachment_id=14981