PUMA Test Facility

 

With the PUMA facility MPE modernizes once again its former ZETA-Lab to meet the challenges of forthcoming X-ray astronomy activities. The aim is to have on-site a small high-technology test facility for universal purposes to perform precise measurements on focal instrumentations of X-ray telescopes, e.g. the absolute calibration of cooled semiconductor detectors or novel type filters.

In the past MPE maintained at the ZETA-Lab a medium-sized facility for scattering low energy X-rays to investigate components for X-ray telescopes, for X-ray cameras, and for monitoring instruments. The employment spectrum of the facility reached from methodological studies on probes for a range of suitable materials over functionality tests of systems to calibrations of high-sensitive measurement intruments.

 

The nearby sketch shows an overview of the test facility. A tunable source provides a bunch of X-rays with energies between 0.1 and 20 keV. The following collimator system mounted inside a vaccum tube blinds out a parallel X-ray beam from this bunch which can be scattered on test specimen (e.g. mirrors, gratings, filters) inside the specimen chamber. The scattered X-rays will be detected by a proportional counter in the detector chamber. Focalplane instruments can be calibrated in the experimental chamber.

The ZETA Test Facility, proved already since more than twenty years, was always modernized and adapted to state of the art to meet the requirements of progressive projects. In 1991 the data acquisition system was rebuilt and connected to MPE's computer net. Lastly a multi-target X-ray source was developed, installed, and calibrated in 1995 to be able to measure the efficiency of new developed transmission gratings.

The various projects performed at the ZETA test facility over the years are compilated in the following table overview.
 

Measurement Programme at the ZETA Test Facility from 1977 to 1998

Project	Test Objects	Time Span
Rocket Experiments	position sensitive proportional counter	1977 - 1987
ROSAT	monitor mirrors, telescope mirror specimen, position sensitive proportional counter PSPC	1977 - 1990
ROSAT/WFC	(WFC)	1987 - 1990
EXOSAT		1980 - 1982
MIR-HEXE		1981
AXAF	efficiency measurement of transmission gratings	1982 - 1996
SAX		1985 - 1994
JET-X		1990 - 1997
SOHO/CDS	surface contamination of control mirrors of the Coronal Diagnostic Spectrometer (CDS)	1991 - 1994
XMM	filter for light suppression, functionality test of pn-CCDs for the EPIC camera	1987 - 1998
ABRIXAS	functionality test of pn-CCDs, scattering properties of plane mirror samples	1995 - 1998