E99007 , GEp(II)
Measurement of the ratio Ge/Gm
for the proton
from Q2
= 3.5 GeV2 to 5.6
GeV2
using recoil polarization
technique
November 3rd - December 22nd,
2000
The idea of online analysis is to check
the quality of the data as they arrive, and fix problems as soon as possible.
In Hall A, the data analysis is done
by the FORTRAN program ESPACE. The output of ESPACE is a hbook file, containing
all histograms and ntuples you asked ESPACE to fill. You can then look
at these plots in PAW, or PAW++. A hbook file is created each time you
run ESPACE, and you typically run ESPACE once per run.
A .kumac file, defining all histograms
and ntuples that are interesting to look at for online analysis, is the
input of ESPACE. These files are already written, and all you have to do
is to ask ESPACE to read them. Here is the procedure:
Go
to ESPACE:
-
log on adaql1 or adaql2,
as adaq user.
-
type goespace (leads you to the good directory)
-
set the environment variable by typing setenv
HALLA_DIR /adaql1/home/espace
-
type the command espace_gep
-
at the ESPACE prompt, choose what you
want to analyze:
FOR EACH RUN:
-
the detectors (HRS + FPP + quick look
at calo)
-
type exec
espace_kumac/e99007_det
-
answer the different questions (first event is 1, last event
is up to you, but a good number is 30000)
-
congratulations ! you just created a hbook file, called hbook/fpp_e99007_det_[runnumber].hbook
!
-
some interesting physics quantities
-
type exec espace_kumac/e99007_phys
-
answer the different questions (first event is 1, last event
is up to you, but a good number is 30000)
-
congratulations ! you just created a hbook file, called hbook/fpp_e99007_[runnumber].hbook
!
TWICE A SHIFT:
-
a closer look at the calorimeter
-
type exec
espace_kumac/e99007_calo
-
answer the different questions (first event is 1, last event
is up to you, but a good number is 100000)
-
congratulations ! you just created a hbook file, called hbook/fpp_e99007_calo_[runnumber].hbook
!
-
the FPP chambers efficiency
-
type exec
espace_kumac/straw_eff
-
congratulations ! you just created a hbook file, called hbook/straw_eff_[runnumber].hbook
!
Go to PAW++:
-
choose what you want to look at:
-
detectors (HRS + FPP + quick look at calo)
-
type exec paw_kumac/e99007_det
-
look at the histograms and compare with reference : ADC and
TDC spectra of the scintillators, hit multiplicity in the VDCs, straw maps
of the FPP chambers, TDCs of the FPP chambers, demux of the FPP chambers,
hit multiplicity in the FPP planes, and finally ADC, TDC and number
of counts in elastic peak for each calo block.
-
the physics quantities
-
type exec paw_kumac/e99007_phys
-
look at the histograms and compare with reference
-
a closer look at the calorimeter
-
type exec paw_kumac/e99007_calo
-
look at the histograms : raw ADC spectra, raw TDC spectra
and ADC spectra cut on TDC elastic peak (display comes with 9 blocks
of the same row in one page), number of blocks in the selected cluster
(.mult) , total number of clusters reconstructed in the calo (.nclus),
and identification of the cluster whose position is correlated with the
position of the proton (.id = 0 if biggest cluster, .id=1 if second biggest,
etc..., .id=-2 if no cluster is correlated with proton)
-
the FPP chambers efficiency
-
type exec paw_kumac/straw_eff
-
look at the histogram
-
grab the screens and make an HALOG entry
If you have any questions or suggestions about online
analysis, don't hesitate to let us know ! We are pretty available...