DAQ+trigger are both happy, Compton will take data early on, and may
change the beam tune somewhat.
_ re-check the slits. I've noticed that sometimes people report rate measuraments
using a slow counting trigger such as phys0 as their guide. This method will give
large errors! You should always use the fastest counting trigger you have, f.i. L
and R-sector singles, which are in the 10's of KHz region. Also, be aware that the
background is not linear which will give you a bias/systematic in the 10-15% region.
Please refer to page 58, 59 of logbook 5, and other logbooks. Try also
"visual_scaler -i 10" for longer measurament times
_ Re-connect the Wch TDC cables in the left-sector fb crate
_ Measure rate (at comparable currents) with and wthout the slits, with
and without a 0 and 0.2 SCCM target. If the rate is way off, do slits
adjustments. Else move on
_ Check ring vacuum levels to see that you are effectively flowing gas.
The ring is an excellent flowmeter! (its pumping speed is constant)
_ You should use the elastic_coincs.settings.
Again, there is a tendency to multiply trigger files using evocative suffixes (_2,
_Improved, _friday). I find this just confusing, it will also give errors since all
trigger files should have the same delays, and-or combinations. Right now there are
3 cosmic, 1 flasher, 1 NC and two ep triggers: elastic_coincs (which is "restricted")
and any_coincs.
I don't think you need more. Just edit the trigger from the gui to add/change
something !! *ALL* trigger files ever downloaded since about 7/20 have been
saved in the ./archive directory. Even if the file changed name/contents you
can still find out what was downloaded. At any rate, please check the trigger
you are using, do not just assume you have the right trigger
_ Take a 0.2 SCCM run and if possible an empty run
_ Turn HV and gas flow off
_ 00:00 -> 08.00 shift is only ABS and beam development.
_ The hall will open every day of this week until at least thursday.
________________________________________________________________________________
Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124
research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:28 EST