There has been significant progress since the last newsletter was issued.
Some highlights are included below.
>>> FORWARD ANGLE CALORIMETER RECONSTRUCTION IN RECSIS <<<
A great deal of progress has been made on the forward angle calorimeter
reconstrucion code.
Serguei Boiarinov (ITEP) has nearly completed development of a set of standard
tests to be applied to the reconstruction code as it evolves in order to
measure improvements. These tests are being implemented in RecSis, and required
modification of GSIM. He also implemented the BOS result bank which had been
defined by the calorimeter group, which contains reconstructed data for showers.
He installed GSIM and RecSis on the ITEP computers for further development.
Almost all of this work was done remotely from ITEP.
TY Tung (W&M) added individual attenuation lengths calculation to existing
reconstruction code. (Previously this code assumed only a single attenuation
length)
Stepan Stepanyan (YerPhI) has evaluated the reconstruction efficiency of the
existing code. He identified several sources of reconstruction inefficiency and
modified the cluster-finding routine to eliminate them. Presently the efficiency
is greater than 99.9% for single-electron and single-photon events of energy
>0.25 GeV . He measured the energy resolution to be 8%/sqrt(E), consistent with
previous results. He determined the sampling fraction to be 0.272 for energies
of 1 GeV and greater. He also tested the multiple-hit reconstruction algorithm
in the existing code. He implemented and tested a new BOS result bank which
contains information at the "hits" level. He also added the option of a more
precise use of the individual attenuation lengths (which requires somewhat more
CPU time). He repaired the previously 'broken' timing reconstruction. He
expanded the number of TCL control variables to give more flexibility to the
reconstruction scheme.
Cole Smith (UVA) has defined a prototype specification for the calibration bank
for the calorimeter. Currently calibration parameters are contained in common
blocks in the code. He is in the process of writing RecSis routines to read in
the calibration BOS banks.
Ralph Minehart (UVA) has written an extensive document which defines the
calorimeter geometry in terms of a small number of parameters, and presents
transformation equations using these parameters to connect the relevant
reference frames. He also includes a scheme for corrections to the ideal
parameters, to represent the as-built, as-installed geometry.
David Heddle (CNU) has implemented the parameters defined in Ralph's document
into a new BOS geometry bank for the calorimeter. Currently the reconstruction
uses parameters in common blocks to define the geometry.
>>> FORWARD ANGLE CALORIMETER SIMULATION IN GSIM <<<
Maurik Holtrop (UNH) has joined the GSIM effort. He has installed the GSIM
program on the UNH Silicon Graphics computers and on the CEBAF Sun computers.
He has been working hard to pinpoint the sources of the GSIM crashes which have
hindered development of calorimeter commissioning software for over half a year.
>>> CERENKOV COUNTER RECONSTRUCTION IN RECSIS <<<
Alex Vlassov (ITEP) has installed the cerenkov counter reconstruction code into
recsis, along with Arne Freyberger (TJNAF). He has defined a geometry bank, a
first-pass result bank, and a calibration bank, and implemented them into the
code. He has tested the recsis implementation of the reconstruction code
extensively with GSIM events.
>>> CERENKOV COUNTER SIMULATION IN GSIM <<<
Alex Vlassov (ITEP) installed the Cerenkov counter simulation in GSIM months
ago and continues to test and improve it in conjuction with the reconstruction
code. He has produced many results based on this simulation, such as studying
the optimal summing scheme for the Cerenkov counter electronics.
>>> LARGE ANGLE CALORIMETER SIMULATION IN GSIM <<<
Harout Avakian (INFN Frascati) installed the large angle calorimeter in GSIM
months ago and has been testing it for some time.
>>> LARGE ANGLE CALORIMETER RECONSTRUCTION IN RECSIS <<<
Harout Avakian (INFN Frascati) has installed the large angle calorimeter in
RecSis, along with Arne Freyberger (TJNAF). He has defined the BOS output bank,
calibration bank, and geometry bank for this code, which has been tested
external to RecSis for quite some time, including tests with the cosmic ray
test data.
>>> BOS & PAW <<<
Cole Smith (UVA) has been looking into options for making use of the power and
flexibility of PAW in the context of the BOS data structure. He has developed
a macro library which can be used by PAW to read in and write to BOS banks.
These will be used for calibration of the calorimeters, among other uses.
>>> CALIBRATION AND COMMISSIONING STUDIES/SOFTWARE DEVELOPMENT <<<
Stepan Stepanyan (YerPhI) has studied pi-0 reconstruction and e/pi separation
in the forward calorimeter. He has written a 24-page description of his studies
over the last few months using the reconstruction code in RecSis, and
documenting the current status of the code. He measured a 98.2% electron
efficiency, 3.75% pion efficiency, and pi/e ratio of 3.8x10^-2 in a study
making use of cuts on total energy, balance between inner and outer energy,
and cuts on the averages of the second moments and the quadrature of the third
moments of the energy loss distributions. His studies of pi-0 reconstruction
indicates a calculated mass width of 12-16 MeV. He also showed the calorimeter
can separate protons from electrons and pions rather well in a plot of the
energy deposit as a function of flight time. These studies have also given
valuable experience in using GSIM and CELEG.
Alan Coleman and Herb Funsten (W&M) are studying the measurement of the
attenuation functions in the forward calorimeter using a minimum ionizing
particle, one-pixel cut. This is intended to verify and extend an earlier
study performed by TY Tung.
Marco Ripani and Vladimir Sapunenko (INFN Genoa) have made good progress in
studying pion production reactions in the large angle calorimeter. They have
installed the GSIM package on their HP computer, and modified their single
pion event generator to include data management and disk storage using BOS.
They have gotten GSIM to process this data and can display it using CED.
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>>> SOME REMAINING TASKS, FORWARD CALORIMETER <<<
Create calibration bank (and/including attenuation bank) for reconstruction
code; implement geometry bank and calibration bank into reconstruction code;
implementation of error calculation on output variables; further documentation
of the reconstruction code; get experience with reconstructing simulated CLAS
data; write general routine for matching multiple inner and outer hits,
including energy balances and time calculation; test and improve the position
reconstruction; recover the 'lost' beam-target background generator for GSIM,
and use it for simulations; study calibration reactions and write standalone
code to do the calibrations; develop scheme and software for online monitoring.