Development of the CCD-based XRS instrument onboard SELENE

Abstract

The SELENE (SELenological and Engineering Explorer) is a Japanese lunar polar orbiter and performs lunar global mapping with more than 10 scientific instruments. The XRS will map major elemental composition in 20km spatial resolution and provide the clue to understanding the lunar evolution. For that purpose, the XRS has been designed to improve energy resolution and efficient detection area. Then the X-ray detector has arrays of CCD with 100cm² detection area, and is kept below -50C by radiation cooling. Ultra-thin beryllium window are developed for better transparency at low energy. We present the specification and the current status of the XRS as prepared for the interface test, as well as the plan of pre-flight tests and observation plan.