A&A Supplement series, Vol. 122, April II 1997, 309-326
Received May 15; accepted July 2, 1996
A.N. Parmar - D.D.E. Martin - M. Bavdaz - F. Favata - E. Kuulkers - G. Vacanti - U. Lammers - A. Peacock - B.G. Taylor
Send offprint request: A.N. Parmar:aparmar@astro.estec.esa.nl
Astrophysics Division, Space Science Department of ESA,
ESTEC, Postbus 299, 2200 AG Noordwijk, The Netherlands
The payload of the Italian/Dutch spacecraft BeppoSAX includes a set of
four X-ray concentrators each of geometric area 
together with imaging gas scintillation proportional
counter detectors located at the focal planes.
One of these detectors, the Low-Energy Concentrator Spectrometer (LECS),
is sensitive to X-rays in the energy
range 0.1-10 keV, while the other three cover a narrower energy
range of 1.3-10 keV.
In order to achieve the extended low-energy response of the LECS a novel type
of gas scintillation proportional counter has been developed which dispenses
with the separate drift and scintillation regions of conventional
instruments.
The design and performance of the instrument together with
its calibration and data analysis system are described here.
keywords: instrumentation: detectors -- methods: data analysis -- methods: observational -- techniques: spectroscopic -- X-rays: general