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Title: LAr calorimeter for SCC with a common vacuum bulkhead---a concept to improve hermeticity

Abstract

A new concept for a Barrel/Endcap LAr Calorimeter (LAC) is described in which the Barrel and Endcaps are in separate vacuum enclosures but share a common vacuum bulkhead (CVB). We explore 2 possible bulkhead construction types; welded plate sandwich panels, and brazed sandwich panels in which the core is an isotropic cellular solid--foamed aluminum. Gas lines and electric cables from he innermost Drift Chamber pass through radial holes in the core of the sandwich bulkhead. The CVB concept offers the potential to obtain a more hermetic calorimeter with significantly reduced dead material and/or space in the interface region common to conventional design LAr detectors for the SSC with Endcap features. To utilize a common additional steps to remove the Drift Chamber, a large increase in Endcap standby heat leak, and perhaps, new cryogenic safety issues. We find that significant amount of dead mass can be removed from critical regions of the vacuum shells when compared to a promising SSC LAC reference design. It is also shown that the increased standby heat leak of this concept can be easily removed by existing cooling capacity in another large LAr calorimeter. It is further shown that shut-downs need not be appreciably longer. Finally,more » it is argued that cryogen spill hazards can be avoided if the Endcap's LAr is removed during Drift chamber maintenance shutdowns, and that cryogenic safety is not compromised.« less

Authors:
 [1];  [2]
  1. Lawrence Berkeley Lab., CA (USA)
  2. Stanford Linear Accelerator Center, Menlo Park, CA (USA)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
DOE/ER
OSTI Identifier:
7247479
Report Number(s):
LBL-27394
ON: DE90008055; TRN: 90-026756
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; SHOWER COUNTERS; MODIFICATIONS; DESIGN; DRIFT CHAMBERS; REFRIGERATION; SUPERCONDUCTING SUPER COLLIDER; VACUUM SYSTEMS; COOLING; MEASURING INSTRUMENTS; MULTIWIRE PROPORTIONAL CHAMBERS; PROPORTIONAL COUNTERS; RADIATION DETECTORS; STORAGE RINGS; 440104* - Radiation Instrumentation- High Energy Physics Instrumentation

Citation Formats

Pope, W L, and Watt, R D. LAr calorimeter for SCC with a common vacuum bulkhead---a concept to improve hermeticity. United States: N. p., 1989. Web. doi:10.2172/7247479.
Pope, W L, & Watt, R D. LAr calorimeter for SCC with a common vacuum bulkhead---a concept to improve hermeticity. United States. https://doi.org/10.2172/7247479
Pope, W L, and Watt, R D. 1989. "LAr calorimeter for SCC with a common vacuum bulkhead---a concept to improve hermeticity". United States. https://doi.org/10.2172/7247479. https://www.osti.gov/servlets/purl/7247479.
@article{osti_7247479,
title = {LAr calorimeter for SCC with a common vacuum bulkhead---a concept to improve hermeticity},
author = {Pope, W L and Watt, R D},
abstractNote = {A new concept for a Barrel/Endcap LAr Calorimeter (LAC) is described in which the Barrel and Endcaps are in separate vacuum enclosures but share a common vacuum bulkhead (CVB). We explore 2 possible bulkhead construction types; welded plate sandwich panels, and brazed sandwich panels in which the core is an isotropic cellular solid--foamed aluminum. Gas lines and electric cables from he innermost Drift Chamber pass through radial holes in the core of the sandwich bulkhead. The CVB concept offers the potential to obtain a more hermetic calorimeter with significantly reduced dead material and/or space in the interface region common to conventional design LAr detectors for the SSC with Endcap features. To utilize a common additional steps to remove the Drift Chamber, a large increase in Endcap standby heat leak, and perhaps, new cryogenic safety issues. We find that significant amount of dead mass can be removed from critical regions of the vacuum shells when compared to a promising SSC LAC reference design. It is also shown that the increased standby heat leak of this concept can be easily removed by existing cooling capacity in another large LAr calorimeter. It is further shown that shut-downs need not be appreciably longer. Finally, it is argued that cryogen spill hazards can be avoided if the Endcap's LAr is removed during Drift chamber maintenance shutdowns, and that cryogenic safety is not compromised.},
doi = {10.2172/7247479},
url = {https://www.osti.gov/biblio/7247479}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Nov 01 00:00:00 EST 1989},
month = {Wed Nov 01 00:00:00 EST 1989}
}