Development of soft x-ray large solid angle camera onboard WF-MAXI

Masashi Kimura*, Hiroshi Tomida, Shiro Ueno, Nobuyuki Kawai, Yoichi Yatsu, Makoto Arimoto, Tatehiro Mihara, Motoko Serino, Hiroshi Tsunemi, Atsumasa Yoshida, Takanori Sakamoto, Takayoshi Kohmura, Hitoshi Negoro

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Wide-Field MAXI (WF-MAXI) planned to be installed in Japanese Experiment Module "Kibo" Exposed Facility of the international space station (ISS). WF-MAXI consists of two types of cameras, Soft X-ray Large Solid Angle Camera (SLC) and Hard X-ray Monitor (HXM). HXM is multi-channel arrays of CsI scintillators coupled with avalanche photodiodes (APDs) which covers the energy range of 20 - 200 keV. SLC is arrays of CCD, which is evolved version of MAXI/SSC. Instead of slit and collimator in SSC, SLC is equipped with coded mask allowing its field of view to 20% of all sky at any given time, and its location determination accuracy to few arcminutes. In older to achieve larger effective area, the number of CCD chip and the size of each chip will be larger than that of SSC. We are planning to use 59 x 31 mm2 CCD chip provided by Hamamatsu Photonics. Each camera will be quipped with 16 CCDs and total of 4 cameras will be installed in WF-MAXI. Since SLC utilize X-ray CCDs it must equip active cooling system for CCDs. Instead of using the peltier cooler, we use mechanical coolers that are also employed in Astro-H. In this way we can cool the CCDs down to -100C. ISS orbit around the earth in 90 minutes; therefore a point source moves 4 arcminutes per second. In order to achieve location determination accuracy, we need fast readout from CCD. The pulse heights are stacked into a single row along the vertical direction. Charge is transferred continuously, thus the spatial information along the vertical direction is lost and replaced with the precise arrival time information. Currently we are making experimental model of the camera body including the CCD and electronics for the CCDs. In this paper, we show the development status of SLC.

Original languageEnglish
Title of host publicationSpace Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray
ISBN (Electronic)9780819496126
Publication statusPublished - 2014
Externally publishedYes
EventSpace Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray - Montreal
Duration: 2014 Jun 222014 Jun 26


OtherSpace Telescopes and Instrumentation 2014: Ultraviolet to Gamma Ray


  • ISS Kibo WF-MAXI

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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