| Popis: |
We will describe the development of the design and processing of the near ultraviolet (NUV, 1800 - 3000A) and far ultraviolet (FUV, 1350 - 1800A) sealed tube microchannel plate (MCP) cross delay line (XDL) detectors for the NASA Galaxy Evolution Explorer Satellite (GALEX). Specifications for the two detector systems for GALEX define a large 65mm diameter circular format, with high spatial resolution ( 2 x 10 5 events sec -1 . We have implemented a detector design using a microchannel plate Z stack to amplify the signals detected by the photocathodes, and a cross delay line anode to provide the photon event position encoding. These detectors were produced using a new sealed tube production facility installed at the Space Sciences Laboratory, University of California, Berkeley. The basic designs for both the NUV and FUV detectors are nearly identical. They differ only in the entrance window material (MgF 2 for the FUV and SiO 2 for the NUV), and the photocathode type and configuration (NUV is proximity focus CsTe. FUV is CsI opaque on the MCP). The vacuum process chamber design, process tooling, and procedures were substantially different, however. We will discuss the two procedural approaches and describe the significance of the techniques employed. |
