The main purposes of using ESPACE for HAPPEX are: 1) To check the detector alignment relative to the VDCs; 2) To measure the Q^2 (momentum transfer); 3) To look at the attenuation in the HAPPEX detector and judge if it is degrading. 4) To study backgrounds.
In addition, several consistency checks must be done, to verify detectors are functioning and to check the calibration of the spectrometer.
R. Michaels, March 31, 1999
(pager: 9-680-7410, e-mail: rom@jlab.org)
This file : ~adev/parity/README
(Note that as I write this, /home/adev is not the same
as ~adev on the linux machines. Be careful.)
1. First do a CODA run with spectrometer DAQ. See separate
instructions in the counting room or on Hall A web page
www.jlab.org/Hall-A/equipment/daq/guide.html, etc.
One thing that is new and important for HAPPEX is that
when you start the run, a TCL/TK window pops up which
asks you to enter the header information for ESPACE.
Make sure it is filled out correctly.
2. Now to run ESPACE, go to ~adev/parity on adaql1.
(It runs on Linux machines adaql1,l2, or Suns adaqs2,s3).
This is the same account from which you ran CODA.
3. If you did the right thing when you started a CODA run
and entered the header info for ESPACE (see 1.), you're
header file exists already in ~adev/parity/header/hdr_NNN
where NNN is the run number. Otherwise, you'll have to
create this file by hand (copy from an old run, modify
appropriately). The important quantities are the energy,
magnetic fields, spectrometer angles, and trigger types.
4. Type "espace" (without the quotes, of course)
5. At the espace> prompt, type "ana_parity".
Answer the obvious questions about run number,
how many events (the default for 5000 takes a few
minutes and is adequate), and disk where data was
written (probably data1 or data2).
6. If you get some messages like the following, ESPACE
is running normally (the "errors" from HDELET are
unimportant, also the "READ_SHOW_COEF" messages).
HAPPEX Trigger:
Will not use scint corrections
Will use database for happex: db_happex
Using header info, we will assume :
E-arm at 12.5280 degrees or 0.21865 radians
H-arm at 12.5580 degrees or 0.21918 radians
Beam energy 3364.42 GeV
happex trigger type = happex
7. At the end you get a message that's something like this:
319 spectra saved to disk file.
8. Exit espace ("exit"). If you were in paw, exit paw first
unless you know better.
9. Now go into paw, open the file spec_NNN.hbook, where
NNN = run number. (e.g. "h/file 21 spec_2685.hbook")
Where is the hbook file ? This depends on the line
"set/file/output" in ana_parity.kumac. If we run on
adaqs2 its fine to put the hbook into the local directory
which is on a adaqs2 disk. If we run on adaql1 we will
put the hbook files into /adaql1/data1/parity/online_hbook.
To open file: In paw type "exec open_file NNN".
10. Check alignment: Exec the kumac xypar, i.e. "exec xypar".
The results go into a postscript file xypar.ps which can
be printed. Alignment is best checked with scint trigger.
11. To get the attenuation curves for the 2 spectrometers,
"exec atten". Result is in atten.ps
12. To check the Q^2, "exec qsq". Result in qsq.ps
Q^2 is best checked with a HAPPEX trigger run.
13. For low-level detector checks (recommended with scint trig),
type "exec detcheck", result in detcheck.ps
R. Michaels -- e-mail: rom@jlab.org