MCP Quantum Efficiency

(with no UV Ion Shield)

Below are the current and historic calibration products for the HRC MCP Quantum Efficiency.

The most recent models are:

Flight v2.2 for the HRC-I (Oct 2003 by J. Posson-Brown, R. H. Donnelly, and D. Pease ) - in CALDB as of v2.25
Flight v4 for the HRC-S (Nov 2004 by D. Pease) - in CALDB as of v. 3.0.1 (CALDB file hrcsD1999-07-22qeN0007.fits)

HRC-I

Product	SAC (XRCF) (settings)	AO-1	XRCF	SAC (Flight) (settings)	Flight
Data	v1 v2	-	v1 v2	v1 v2	v1 v2, v2.1 v2.2
Model	v1,v2	v1	v1 v2 v3	v1 v2	v1 v2 v2.1 v2.2
Plot	v1,v2	v1	v1,v2,v3	v1,v2	v1 v2 v2.1 v2.2
IPI Link	->	-	-	->	-

HRC-S

Product	SAC (XRCF) (settings)	AO-1	XRCF	SAC (Flight) (settings)	Flight
Data	v1	-	v1 v2	v1	v1
Model	v1 v2	v1	v1 v2 v3	v1 v2	v1 v2 v2.1* v3 v4
Plot	v1,v2	v1	v1,v2,v3	v1,v2	v1,v2,v3,v4
IPI Link	->	-	-	->	-
*Flight model v2.1 & v3 include small updates to UVIS Carbon edge and QEU

The QEs compiled above have not had any PHA filter applied. The entire range from 0 to 255 is accepted. However, the HRC has a commandable event trigger threshold, the values of which were established for each of the HRC instruments during the post-XRCF measurements at SAO.

These trigger settings are not commandable by the observer, and will remain at their preset levels (trigger level 8) for the duration of the mission unless there is some compelling reason to change them.

The threshold for a given instrument produces a cutoff in the pulse height spectrum, which for HRC-S is about PHA level 25 and is not sharp. Thus the hardware excludes certain PHAs. Any simulation of a spectrum will have to take the cutoff into account.

Documents:

Discussion of In-flight HRC-I MCP QE Calibration:
- "An Update to the HRC-I Quantum Efficiency Model" (model v2.2)
  J. Posson-Brown, R. H. Donnelly, and D. Pease (27 October 2003)
- "A New Flight Model of the HRC-I MCP Quantum Efficiency" (model v2.1)
  K. T. Hole, R. H. Donnelly, and J. Posson-Brown (6 August 2002)
Discussion of In-flight HRC-S MCP QE Calibration:
- 2004 Chandra Calibration Workshop
- In-flight Effective Area Calibration of the Chandra LETGS (SPIE, Waikoloa 2002)
- Low Energy Effective Area of the Chandra LETGS (SPIE, Munich 2000)
- (Poster) Mid-Energy Effective Area Calibration of the Chandra LETGS (HEAD, Honolulu 2000)
- See also LETG Calibration page
Results from the ASC analysis of both detectors:
"Effective Area of the AXAF high resolution camera (HRC)"
Patnaude, Pease, Donnelly, Juda, Jones, Murray, Zombeck, Kraft, Kenter, Meehan, Elsner, and Swartz
SPIE paper July 1998.
Discussions by the HRC IPI team on in-flight broadband EA/QE verification (Excerpts from 2000, Proc. SPIE Vol. 4012):
HRC-I (Kenter, et al.) HRC-S (Kraft, et al.)
Calibration memo discussing out of band response of the HRC-I:
"HRC-I response to out of band radiation"
M. Zombeck, March 1999

Contact CXC Calibration (cxccal@cfa.harvard.edu) for further information.

Last modified: 09/27/12

Chandra Science | Chandra Home | Astronomy links | iCXC (CXC only) | Search

The Chandra X-Ray Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory.
60 Garden Street, Cambridge, MA 02138 USA. Email: cxcweb@head.cfa.harvard.edu
Smithsonian Institution, Copyright © 1998-2004. All rights reserved.