| Version |
$Revision: 1.4 $ |
| Last Update |
$Date: 2001/11/08 14:46:10 $ |
| HRC CCB Status |
not reviewed |
Number: HRC-C-002
Type: Constraint
Original Date: 6/13/95 Revised Date: 2/19/98
Subsystem: HRC
Subject: HRC Housing Pressure at MCP HV Turn-on
Source: Informal CARD inputs, e-mail, M. Juda, 9/11/95
CRL Statement:
The HRC Micro-Channel Plate High Voltage (MCP HV) must not be turned ON
if the detector housing pressure is greater than 1.0e-5 Torr.
CRL Rationale/Justification:
Both the vacuum monitor, mounted on the Spacecraft along with the ACA PEA, must
be below 1.0e-5 Torr and the HRC detector housing door must be open for
at least 24 hours before the pressure will be within the design limits
for a safe MCP HV turn ON. The vacuum monitor level reading must be
determined by test, with a Spacecraft venting analysis, to determine
the monitor pressure required to satisfy the HRC detector housing
pressure of no greater than 1.0e-5 Torr.
CRL Impact:
High voltage break-down caused by operating the MCP HV at pressures greater
than 1.0e-5 Torr will damage the HRC.
Recommended Action:
Incorporate into the Systems and Operations Procedures, with ASC providing
the inputs.
$Log: hrc-c-002.html,v $
Revision 1.4 2001/11/08 14:46:10 juda
HTML "href" tag edits to convert to soft links
Revision 1.3 1999/02/08 20:07:13 juda
removed TBDs
Revision 1.2 1998/04/27 13:44:37 juda
Added Version table
Page created 1998 March 4 - Based on 30 Jan 98 release of OP05
Dr. Michael
Juda
Harvard-Smithsonian Center for Astrophysics
60 Garden Street, Mail Stop 70
Cambridge, MA 02138, USA
Ph.: (617) 495-7062
Fax: (617) 495-7356
E-mail: mjuda@cfa.harvard.edu