Design and testing of a compact X-ray diode. 1998 summer research program for high school juniors at the University of Rochester's Laboratory for Laser Energetics. Student research reports

Omega, the University of Rochester's high powered laser dedicated to fusion research gives off x-rays with different energy levels. Measuring the number of x-rays and the energy of each is important in understanding what happens in the target chamber when Omega is fired. Existing x-ray detectors are expensive, big, and cumbersome. Imaging detectors such as x-ray pinhole cameras which record onto film, x-ray framing cameras which make videos, and most often, x-ray streak cameras which measure time dependences of x-rays. They require a lot of maintenance and are difficult to keep operational. Lawrence Livermore National Laboratory has developed the Dante Diode. The Dante diode array on Omega functions as a group of 12 diodes which take up a 24 inch port in the target chamber, making it space-consuming and difficult to move for alternate views. In designing a new detector, space was the main issue. The smallest possible functional diode, without losing accuracy was desired. Since the laser pulse only lasts a few nanoseconds it is important that the x-ray detector have a response time of a few tenths of a nanosecond. Other criteria include that it be easy to use for measuring the energy and number of x-ray photons and that cost be kept down. This report discusses the design process and testing of the new diode