Reflectivity and polarization sensitivity of a bent crystal with DLC deposition

Ryo Iizuka; Shingo Kusunoki; Atsushi Tokuno; Yohko Tsuboi; Seiya Takeda; Satoshi Yamamuro; Kazuyoshi Misumi; Hiroki Akasaka; Naoto Ohtake; Masanori Saito

doi:10.1117/12.857965

29 July 2010 Reflectivity and polarization sensitivity of a bent crystal with DLC deposition

Ryo Iizuka, Shingo Kusunoki, Atsushi Tokuno, Yohko Tsuboi, Seiya Takeda, Satoshi Yamamuro, Kazuyoshi Misumi, Hiroki Akasaka, Naoto Ohtake, Masanori Saito

Author Affiliations +

Proceedings Volume 7732, Space Telescopes and Instrumentation 2010: Ultraviolet to Gamma Ray; 77324R (2010) https://doi.org/10.1117/12.857965
Event: SPIE Astronomical Telescopes + Instrumentation, 2010, San Diego, California, United States

Abstract

We report a development of a bent crystal for use of X-ray polarimeter. A Si(100) crystal sheet was deposited with DLC (Diamond-Like Carbon) and bent by the difference in the internal stress between the DLC and Si. An angular reflectivity of the crystal was measured at 8 keV (Cu-Kα). The center of the reflection peak appeared at the Bragg angle expected for the (400) plane of Si(100). With the bending of the crystal, the angular width of the peak is broadened. A sample indicated the angular width of 2 degree, which is equivalent to the energy width of 0.5 keV. The modulation factor was measured to be more than 0.9 for 8 keV energy emission. If the energy of the X-ray emission is at Fe-K lines (~7 keV), which are very important for X-ray astronomy, the Bragg angle becomes more close to 45 degree. It means that higher sensitivity for the polarization would be expected for these lines. The sensitivity in wide energy band with the high modulation factor indicates that the bent crystal can be a new tool for the X-ray polarimeter. A preliminary design of the polarimetric optics composed by the Si(100) crystal and a small-size detector (e.g. X-ray CCD camera) is proposed. For celestial objects with large spatial extent with large emitting energy band, our optics could collect X-rays much more efficiently than existing optics with high signal to noise ratio. Any kind of crystals can be bent with our method, and then a combination of different crystals will further improve the performance of the polarimetric optics.

Citation Download Citation

Ryo Iizuka, Shingo Kusunoki, Atsushi Tokuno, Yohko Tsuboi, Seiya Takeda, Satoshi Yamamuro, Kazuyoshi Misumi, Hiroki Akasaka, Naoto Ohtake, and Masanori Saito "Reflectivity and polarization sensitivity of a bent crystal with DLC deposition", Proc. SPIE 7732, Space Telescopes and Instrumentation 2010: Ultraviolet to Gamma Ray, 77324R (29 July 2010); https://doi.org/10.1117/12.857965

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available