Marta Lewandowska with Corbin Covault

 Development of a CCD-Based Photometry System for Atmospheric Monitoring

High-energy astrophysical gamma rays produce extensive air showers when they strike the upper atmosphere of the Earth.  The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) collects the Cherenkov radiation produced in these air showers via an array of solar heliostat mirrors.  Because STACEE uses the atmosphere to detect gamma rays, careful monitoring of atmospheric conditions is necessary in order to accurately calibrate the detector.

     The STACEE Atmospheric Monitor (SAM) is a system for automated real-time photometry and cloud detection.  It consists of a photomultiplier tube placed in the eyepiece of a computer-controlled Meade 8″ LX200 Schmidt-Cassegrain telescope, controlled and read out by a serial link to a PC.  Due to the  photometer’s narrow (8 arcminutes half-angle) field of view, the absolute pointing and tracking of the telescope must be accurately calibrated and maintained.  The goal of the project is to design and construct a secondary optic outfitted with a CCD for the purpose of verifying the pointing of the telescope, and relaying that image to the control room.  This addition will provide an alternative to the current photometric system.  Once this optic is constructed, it will be mounted onto the telescope at the STACEE site in New Mexico and tested.  If time allows, STACEE data will be taken, and work will be done to integrate the new optic into the photometry system.