The PHENIX electromagnetic calorimeter Page: 2 of 7
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
basis of their energy and velocity.
Since hadrons will be more copiously produced than electrons, approximately
106 rejection against hadrons is required. The PHENIX EM calorimeter provides
about a factor of 100 rejection from lineshape alone at 1 GeV/c [1] ,but this tool be-
comes less effective at lower energies. We studied ways to obtain additional hadron
rejection with the calorimeter using both longitudinal shower shape measurement
and time of flight measurement[1]. Timing performance of this calorimeter is largely
determined by photostatistics, decay constants of the scintillator and waveshifters
and by the speed of the phototube.
The maximum radiation dose at the calorimeter is expected to be < 100
rads/yr due to the large distance from the interaction point and the luminosity(
particle fluxes are equivalent to a pp luminosity of 10S0cms-1 during heavy ion
running). The most radiation sensitive component of our calorimeter is expected
to be the waveshifter fiber [2].
2. Construction of the Calorimeter
The calorimeter is built up out of non-projective modules, each segmented
into 4 optically independent towers. Each tower is made up of 66 alternating layers
of 1.5 mm lead and 4 mm thick injection molded polystyrene based scintillator. On
each face of the scintillating plates there is a white paper reflector . This assembly
is held under compression by 0.12 mm thick steel sheets that are tack welded to the
end plate of the module.
One end plate of the module has an optical fiber connector allowing a spe-
cially prepared quartz fiber to be inserted through the center of the module and
thereby illuminate ,simultaneously, all scintillator plates in each of the four towers
with UV light from the monitoring system (fig. 1).
Each tower is read out by 36 waveshifter optical fibers which penetrate
through holes in the scintillator, are bundled in a dry collet, then cut and pol-
ished. The light from the 7mm fiber bundle is viewed by a 30 mm diameter vacuum
photomultiplier. In most of our tests we have used a 12 stage, green enhanced PMT
( average q.e.= 16% @ 500 nm.) developed within the PHENIX collaboration and
manufactured in Russia, in other cases we have used a Phillips XP2081B which has
similar characteristics.
3. Summary of Calorimeter R&D program during '92-'93
During the last year we focused on the following topics:
. light yield optimization
. monitoring system development
" time of flight optimization and characterization of non-gaussian tails
. longitudinal segmentation
. scintillator tile edge preparation
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Kistenev, E.; White, S.; Belikov, S. & Kochetkov, V. The PHENIX electromagnetic calorimeter, article, December 31, 1993; Upton, New York. (https://digital.library.unt.edu/ark:/67531/metadc794475/m1/2/: accessed April 19, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.