Friday, April 26, 2002, 16:00
WHGA Auditorium
Ch. Regenfus, Univ. Zürich/CERN
Abstract:
The
ATHENA experiment [1] at the low energy antiproton facility at CERN (AD)
is designed for testing fundamental physic principles (CPT, Gravitation)
to a very high degree of precision by comparing cold antihydrogen to
hydrogen. To monitor the production, as well as the spectroscopic
response of antihydrogen atoms, a detector dedicated for the end
products of anti-hydrogen annihilations was developed. To meet the
requirements of low temperature operation (77 K) in a high magnetic
field (4T), compact size, low power consumption and high granularity, a
combination of two layers of each 16 double sided Si-mu-strip detectors
(16 cm long) was chosen, surrounded by 192 pure-CsI-crystals, read out
by UV sensitive photo diodes [2]. The front end electronics (@ 77 K),
realised in CMOS ASIC, features a self triggering capability of the
independent sub detectors.
After a general review of the ATHENA
apparatus, design, construction and lab tests of the detector will be
presented, as well as recent results from the experiment.