Title:              The response of the CGRO COMPTEL determined from Monte
                     Carlo simulation studies.
 Authors:            STACY,J.G.; KIPPEN,R.M.; KAPPADATH,S.C.;
                     MCCONNELL,M.; MORRIS,D.; MILLER,R.; CONNORS,A.;
                     HERSH,B.; RYAN,J.; MACRI,J.; SIMPSON,G.;
                     SCHOENFELDER,V.; STEINLE,H.; VAN DIJK,R.;
                     WILLIAMS,O.R.
 Journal:            Astronomy and Astrophysics Supplement, v.120,
                     p.691-694
 Publication Date:   12/1996
 Origin:             A&A via CDS
 A&A Keywords:       INSTRUMENTATION: DETECTORS, METHODS: NUMERICAL,
                     TELESCOPES, GAMMA RAYS: OBSERVATIONS
 Abstract Copyright: (c) 1996: Astronomy & Astrophysics
 Bibliographic Code: 1996A&AS..120C.691S

                                  Abstract

The COMPTEL collaboration has carried out an extensive series of Monte Carlo
simulation studies to examine the response of the Imaging Compton Telescope
COMPTEL (energy range 0.8 to 30MeV) aboard the Compton Observatory. These
investigations employed the CERN GEANT Monte Carlo package, using a detailed
model of the mass distribution within the COMPTEL experiment. We have
derived the absolute efficiency of the COMPTEL experiment as a function of
photon energy and incidence angle, and present a comparison of simulation
results with pre-launch calibration measurements. Also, we report on a
comprehensive study of the types of photon interactions leading to accepted
COMPTEL telescope events. We briefly describe a new library of monoenergetic
instrument-response functions, individual elements of which can now be
combined to produce the response of COMPTEL to an input source of arbitrary
spectral shape, for use in scientific analysis. A more detailed, complete
report on these simulation studies is currently in preparation and will
complement parallel reports on the instrument calibration and performance,
and background methods and modeling techniques.