Acceptance of ET44 for 1996.
V.Andreev, 20-May-1997
The whole 1996 period of H1 running was split into 25 samples.
For each sub-sample the acceptance of the ET44 was defined
with the procedure described in H1 note #493. The DB then was updated
with the new set of LET1 banks. A complete list of the bank versions
is shown below:
TransActID Rtyp Dtyp 1.Run Words Author Date
1112139 e-p data 147095 46 vladimir 970422
1112140 e-p data 147893 54 vladimir 970422
1112141 e-p data 151573 54 vladimir 970422
1112142 e-p data 153565 54 vladimir 970422
1112143 e-p data 154375 54 vladimir 970422
1112144 e-p data 155369 54 vladimir 970422
1112145 e-p data 155869 54 vladimir 970422
1112146 e-p data 157870 54 vladimir 970422
1112147 e-p data 157908 62 vladimir 970422
1112148 e-p data 157954 54 vladimir 970422
1112149 e-p data 158087 62 vladimir 970422
1112150 e-p data 158371 62 vladimir 970422
1112151 e-p data 159110 62 vladimir 970422
1112152 e-p data 159917 62 vladimir 970422
1112153 e-p data 160680 62 vladimir 970422
1112154 e-p data 161154 62 vladimir 970422
1112155 e-p data 163250 62 vladimir 970422
1112156 e-p data 163834 62 vladimir 970422
1112157 e-p data 165103 62 vladimir 970422
1112158 e-p data 165680 62 vladimir 970422
1112159 e-p data 167407 62 vladimir 970422
1112160 e-p data 168036 62 vladimir 970422
1112161 e-p data 168954 62 vladimir 970422
1112162 e-p data 169740 62 vladimir 970422
1112163 e-p data 170250 62 vladimir 970422
It is necessary to remind that during 1996 the ET44 was operated
in two different modes. Until the H1 run 157908 the ET44 was not
moved and was situated at the distance ~3.1 cm from the electron
beam ("Parking position"). After that, the operation procedure with
the ET44 was changed. When the stable Luminosity is declared by
HERA the ET44 is moved to the "Working position" at the distance
~1.8 cm to the electron beam.
The y-dependence of the ET44 acceptance for the different run
periods are shown in the picture. You can compare it with the same
distribution for 1995. As it was recomended for 1995 data and
also for the analysis 1996 data it is necessary to use the average
acceptance of the ET44 (integrated over some y-range). This y-range
is slightly different for the different H1 runs. For the first part of
the data taking when the ET44 was not moved the more suitable y-range
is 0.04 < y < 0.22 and for the second part of 1996 this range must be
increased up to 0.03 < y < 0.28. More exactly this y-range for the
certain run period can be obtained by using the ACET44(IRUN,Y,MODE)
function.
The systematic error of the acceptance determination of the ET44
is formed by three main parts:
a) uncertainty in the energy scale determination -> 3 %,
b) trigger efficiency -> 1.5 %,
c) error connected with the uncertainty in the position of the ET44
with respect to the electron beam -> 5.5 %.
So the overall systematic error of the acceptance determination
of the ET44 in 1996 must be considered = 6.4 %.