4,061 research outputs found
Absolute Calibration of a Large-diameter Light Source
A method of absolute calibration for large aperture optical systems is
presented, using the example of the Pierre Auger Observatory fluorescence
detectors. A 2.5 m diameter light source illuminated by an ultra--violet light
emitting diode is calibrated with an overall uncertainty of 2.1 % at a
wavelength of 365 nm.Comment: 15 pages, 8 figures. Submitted to JINS
Absolute Calibration of the Auger Fluorescence Detectors
Absolute calibration of the Pierre Auger Observatory fluorescence detectors
uses a light source at the telescope aperture. The technique accounts for the
ombined effects of all detector components in a single measurement. The
calibrated 2.5 m diameter light source fills the aperture, providing uniform
illumination to each pixel. The known flux from the light source and the
response of the acquisition system give the required calibration for each
pixel. In the lab, light source uniformity is studied using CCD images and the
intensity is measured relative to NIST-calibrated photodiodes. Overall
uncertainties are presently 12%, and are dominated by systematics.Comment: 4 pages, 3 figure. Submitted to the 29th ICRC, Pune, Indi
Multi-wavelength Calibration Procedure for the Pierre Auger Observatory Fluorescence Detectors
We present a method to measure the relative spectral response of the Pierre
Auger Observatory Fluorescence Detector. The calibration was done at
wavelengths of 320, 337, 355, 380 and 405 nm using an end-to-end technique in
which the response of all detector components are combined in a single
measurement. A xenon flasher and notch-filters were used as the light source
for the calibration device. The overall uncertainty is 5%.Comment: Submitted to Astroparticle Physics. V2: section 5.2 extended; author
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Left-Right Symmetry and Supersymmetric Unification
The existence of an SU(3) X SU(2)_L X SU(2)_R X U(1) gauge symmetry with g_L
= g_R at the TeV energy scale is shown to be consistent with supersymmetric
SO(10) grand unification at around 1O^{16} GeV if certain new particles are
assumed. The additional imposition of a discrete Z_2 symmetry leads to a
generalized definition of R parity as well as highly suppressed Majorana
neutrino masses. Another model based on SO(10) X SO(10) is also discussed.Comment: 11 pages, 2 figures not included, UCRHEP-T124, Apr 199
Centaurus A at Ultra-High Energies
We review the importance of Centaurus A in high energy astrophysics as a
nearby object with many of the properties expected of a major source of very
high energy cosmic rays and gamma-rays. We examine observational techniques and
the results so far obtained in the energy range from 200 GeV to above 100 EeV
and attempt to fit those data with expectations of Centaurus A as an
astrophysical source from VHE to UHE energies.Comment: 11 pages, 4 figures, accepted for publication in PAS
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