Fine‐pitch CdTe detector for hard X‐ray imaging and spectroscopy of the Sun with the FOXSI rocket experiment

We have developed a fine-pitch hard X-ray (HXR) detector using a cadmium telluride (CdTe) semiconductor for imaging and spectroscopy for the second launch of the Focusing Optics Solar X-ray Imager (FOXSI). FOXSI is a rocket experiment to perform high sensitivity HXR observations from 4 to 15 keV using the new technique of HXR focusing optics. The focal plane detector requires −30°C). Double-sided silicon strip detectors were used for the first FOXSI flight in 2012 to meet these criteria. To improve the detectors' efficiency (66% at 15 keV for the silicon detectors) and position resolution of 75 μm for the second launch, we fabricated double-sided CdTe strip detectors with a position resolution of 60 μm and almost 100% efficiency for the FOXSI energy range. The sensitive area is 7.67 mm × 7.67 mm, corresponding to the field of view of 791′′ × 791′′. An energy resolution of 1 keV (FWHM) and low-energy threshold of ≈4 keV were achieved in laboratory calibrations. The second launch of FOXSI was performed on 11 December 2014, and images from the Sun were successfully obtained with the CdTe detector. Therefore, we successfully demonstrated the detector concept and the usefulness of this technique for future HXR observations of the Sun.

[1]  Tadayuki Takahashi,et al.  Soft gamma-ray detector (SGD) onboard the ASTRO-H mission , 2014, Astronomical Telescopes and Instrumentation.

[2]  K. Kai,et al.  The Hard X-ray Telescope (HXT) for the SOLAR-A mission , 1991 .

[3]  A. Cichocki,et al.  The spectrometer/telescope for imaging X-rays on board the ESA Solar Orbiter spacecraft , 2013 .

[4]  S. Krucker,et al.  PARTICLE DENSITIES WITHIN THE ACCELERATION REGION OF A SOLAR FLARE , 2013 .

[5]  T. Kosugi,et al.  A loop-top hard X-ray source in a compact solar flare as evidence for magnetic reconnection , 1994, Nature.

[6]  Lindsay Glesener,et al.  FIRST IMAGES FROM THE FOCUSING OPTICS X-RAY SOLAR IMAGER , 2014 .

[7]  S. Krucker,et al.  ON THE RELATION OF ABOVE-THE-LOOP AND FOOTPOINT HARD X-RAY SOURCES IN SOLAR FLARES , 2011 .

[8]  J. Brown,et al.  Nonsolar astronomy with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) , 2003, SPIE Astronomical Telescopes + Instrumentation.

[9]  R. Marcinkowski,et al.  ASTRO-H CdTe detectors proton irradiation at PIF , 2015 .

[10]  Kazuyuki Satoh,et al.  Growth and characterization of CdTe single crystals for radiation detectors , 1999 .

[11]  H. Hudson,et al.  CONSTRAINING THE HARD X-RAY PROPERTIES OF THE QUIET SUN WITH NEW RHESSI OBSERVATIONS , 2010, 1009.2918.

[12]  Yasushi Fukazawa,et al.  The Si/CdTe semiconductor Compton camera of the ASTRO-H Soft Gamma-ray Detector (SGD) , 2014, 1509.00588.

[13]  Tadayuki Takahashi,et al.  Development of double-sided silicon strip detectors for solar hard x-ray observation , 2010, Astronomical Telescopes + Instrumentation.

[14]  S. Krucker,et al.  Hard X-Ray Emissions from Partially Occulted Solar Flares , 2008 .

[15]  Lindsay Glesener,et al.  Constraining hot plasma in a non-flaring solar active region with FOXSI hard X-ray observations (Special Issue : Recent results from Hinode) , 2014, 1509.05288.

[16]  Lindsay Glesener,et al.  THE FIRST FOCUSED HARD X-RAY IMAGES OF THE SUN WITH NuSTAR , 2016, 1605.09738.

[17]  Shogo B. Kobayashi,et al.  The Si/CdTe semiconductor camera of the ASTRO-H Hard X-ray Imager (HXI) , 2016 .

[18]  Kazuhiro Nakazawa,et al.  Performance measurements of Al/CdTe/Pt pixel diode detectors , 2007, SPIE Optical Engineering + Applications.

[19]  Yunjin Kim,et al.  Nuclear Spectroscopic Telescope Array (NuSTAR) Mission , 2013, 2013 IEEE Aerospace Conference.

[20]  Yoshiharu Namba,et al.  The ASTRO-H X-ray astronomy satellite , 2014, Astronomical Telescopes and Instrumentation.

[21]  Peter Mao,et al.  The Nuclear Spectroscopic Telescope Array (NuSTAR) , 2010, Astronomical Telescopes + Instrumentation.

[22]  I. Kondo,et al.  The SOLAR-A mission: An overview , 1991 .

[23]  Tadayuki Takahashi,et al.  The Hard X-ray Imager (HXI) for the ASTRO-H mission , 2012, Other Conferences.

[24]  G. Sato,et al.  Improvement of the CdTe diode detectors using a guard-ring electrode , 2004, IEEE Transactions on Nuclear Science.

[25]  Kazuyuki Hirose,et al.  High-resolution Schottky CdTe diode for hard X-ray and gamma-ray astronomy , 1999 .

[26]  C. J. Hailey,et al.  THE FIRST X-RAY IMAGING SPECTROSCOPY OF QUIESCENT SOLAR ACTIVE REGIONS WITH NuSTAR , 2016, 1603.01069.

[27]  A. Shor,et al.  CdTe and CdZnTe materials for room-temperature X-ray and gamma ray detectors , 1998 .

[28]  Motohide Kokubun,et al.  Development of Double-Sided CdTe Strip Detectors for γ-Ray Imaging and Spectroscopy , 2010 .

[29]  Hideyuki Mori,et al.  ASTRO-H Soft X-ray Telescope (SXT) , 2011, Astronomical Telescopes and Instrumentation.

[30]  T. Takahashi,et al.  Fine-Pitch Semiconductor Detector for the FOXSI Mission , 2015, IEEE Transactions on Nuclear Science.

[31]  Tadayui Takahashi,et al.  Recent progress in CdTe and CdZnTe detectors , 2001, astro-ph/0107398.

[32]  T. Takahashi,et al.  High Energy Resolution Hard X-Ray and Gamma-Ray Imagers Using CdTe Diode Devices , 2009, IEEE Transactions on Nuclear Science.

[33]  Hirokazu Odaka,et al.  New CdTe Pixel Gamma-Ray Detector with Pixelated Al Schottky Anodes , 2007 .