(present: MF, TH, TI, RK, ML)
Richard was wondering whether it would be possible to move the
meeting time from 9am to 11am, as it seems unlikely that Rob
and Naoko will participate very often. Tamara pointed out that she
has lab meetings at noon on Friday, but the general feeling was to
keep our meeting short, so that should be ok.
Michel said he will confirm with Rob and Naoko and if it is ok with them
and the reading room is free at that time, the meeting can be moved.
Tamara
now has a basic set of requirements for her analysis.
She plotted sigmaE/E for all but the 3 lowest energies and
finds that it looks good (around 5-15%) with the one exception
of the point at 100 GeV, which is way out compared to the others.
She explains that that run has a double energy peak, which
then of course gives a poor sigma.
She minimized the resolution by adjusting a constant factor C in:
E(emec) + C*E(hec) and used the nA to GeV conversions from the INTAS report.
Next, Tamara will investigate the problem point and study
systematic effects.
Michel
pointed out that we should all read the INTAS report carefully.
Naoko is in contact with Tamara and Michel about HEC HV corrections and
other correction efforts.
Upcoming priorities should include the HV corrections
(particularly in the second wheel), and timing corrections.
Tayfun
reported on his EMEC position analysis.
When he plots the energies of the first and second EMEC compartments
against each other, he finds a pattern of bands and clusters apart
from the strong cluster left by the electron beam.
Some of the structure is very likely due to pions.
What is puzzling is that there are some
events that definitely have energy in the first layer, but show
no signal in the second.
Michel pointed out that it is likely that there are still
out-of-time problems. Another problem could be is that the number of
cells used to look at the electron shower could be too small to
identify a pion shower nicely.
He also recalled that for some past electron runs pion contamination sometimes hit
the calorimeter at a slightly differennt place then do the electrons.
Also, if the bending magnet is used, electrons can occasionaly radiate hard photons.
Margret
mentioned that she completed a new geometry file that
takes care of the cold HEC dimensions in z, but still
uses the warm radial dimensions. Chris Oram is planning to measure
the thermal expansion coefficient of the kapton boards.
When that is done, a next version of the geometry file will
be produced that will have the added columns of rho and drho for
each cell.