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Title: D0 Solenoid Upgrade Project: Vacuum Pumping Calculations for the D0 Solenoid

Abstract

This engineering note documents the calculations done to determine the vacuum pumping speed for the D-Zero solenoid. The raw calculations are attached. A summary of the results are listed. The vacuum pumping speed of the solenoid is determined by the conductance of the pumping path. At higher pressure ranges during initial pumpdown, the conductances will be rather high. Calculations were not done for the transient pumpdown period, only the steady state type pumping situation. The pressure is assumed to be on the order of 10E-7 torr. This is the free molecular flow regime based on Knudsen number. This pressure regime is also where the pumping speed would be least. The conductances were calculated based on pumping helium gas at a temperature of 300 Kelvin. The total conductance of the pumping path from the solenoid to the inlet of the turbomolecular pump is 11.8 L/s. The effective pumping speed of a 1000 L/s turbo pump attached to this pumping path is 11.7 L/s. The minimum required pumping speed for design purposes was set at 4.3 L/s. This value was arrived at by assuming a warm leak size (10E-8 atm-cc/sec) was not detected during fabrication of the solenoid. It is then assumedmore » that the leak leaks cold liquid helium into the vacuum space. With this leak rate, a 4.3 L/s pumping speed would be able to maintain a 2 x 10E-7 torr pressure in the solenoid vacuum jacket. The solenoid would be able to be operated with this small leak with continuous pumping.« less

Authors:
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1031786
Report Number(s):
FERMILAB-D0-EN-348
TRN: US201201%%976
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; DESIGN; FABRICATION; HELIUM; KNUDSEN FLOW; PRESSURE RANGE; PUMPING; SOLENOIDS; TRANSIENTS; TURBOMOLECULAR PUMPS; VELOCITY; Experiment-HEP

Citation Formats

Rucinski, R., and /Fermilab. D0 Solenoid Upgrade Project: Vacuum Pumping Calculations for the D0 Solenoid. United States: N. p., 1993. Web. doi:10.2172/1031786.
Rucinski, R., & /Fermilab. D0 Solenoid Upgrade Project: Vacuum Pumping Calculations for the D0 Solenoid. United States. https://doi.org/10.2172/1031786
Rucinski, R., and /Fermilab. Mon . "D0 Solenoid Upgrade Project: Vacuum Pumping Calculations for the D0 Solenoid". United States. https://doi.org/10.2172/1031786. https://www.osti.gov/servlets/purl/1031786.
@article{osti_1031786,
title = {D0 Solenoid Upgrade Project: Vacuum Pumping Calculations for the D0 Solenoid},
author = {Rucinski, R. and /Fermilab},
abstractNote = {This engineering note documents the calculations done to determine the vacuum pumping speed for the D-Zero solenoid. The raw calculations are attached. A summary of the results are listed. The vacuum pumping speed of the solenoid is determined by the conductance of the pumping path. At higher pressure ranges during initial pumpdown, the conductances will be rather high. Calculations were not done for the transient pumpdown period, only the steady state type pumping situation. The pressure is assumed to be on the order of 10E-7 torr. This is the free molecular flow regime based on Knudsen number. This pressure regime is also where the pumping speed would be least. The conductances were calculated based on pumping helium gas at a temperature of 300 Kelvin. The total conductance of the pumping path from the solenoid to the inlet of the turbomolecular pump is 11.8 L/s. The effective pumping speed of a 1000 L/s turbo pump attached to this pumping path is 11.7 L/s. The minimum required pumping speed for design purposes was set at 4.3 L/s. This value was arrived at by assuming a warm leak size (10E-8 atm-cc/sec) was not detected during fabrication of the solenoid. It is then assumed that the leak leaks cold liquid helium into the vacuum space. With this leak rate, a 4.3 L/s pumping speed would be able to maintain a 2 x 10E-7 torr pressure in the solenoid vacuum jacket. The solenoid would be able to be operated with this small leak with continuous pumping.},
doi = {10.2172/1031786},
url = {https://www.osti.gov/biblio/1031786}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1993},
month = {8}
}