N. Yamane

Inauguration and First Light of the GCT-M Prototype for the Cherenkov Telescope Array

The Gamma-ray Cherenkov Telescope (GCT) is a candidate for the Small Size Telescopes (SSTs) of the Cherenkov Telescope Array (CTA). Its purpose is to extend the sensitivity of CTA to gamma-ray energies reaching 300 TeV. Its dual-mirror optical design and curved focal plane enables the use of a compact camera of 0.4 m diameter, while achieving a field of view of above 8 degrees. Through the use of the digitising TARGET ASICs, the Cherenkov flash is sampled once per nanosecond contin-uously and then digitised when triggering conditions are met within the analogue outputs of the photosensors. Entire waveforms (typically covering 96 ns) for all 2048 pixels are then stored for analysis, allowing for a broad spectrum of investigations to be performed on the data. Two prototypes of the GCT camera are under development, with differing photosensors: Multi-Anode Photomultipliers (MAPMs) and Silicon Photomultipliers (SiPMs). During November 2015, the GCT MAPM (GCT-M) prototype camera was integrated onto the GCT stru...

Current status of hard x-ray characterization of ASTRO-H HXT at SPring-8

We present the current status of hard X-ray telescope developments of ASTRO-H. ASTRO-H is Japans 6th Xray satellite mission following to Suzaku. It will be launched in 2014. The HXT onboard ASTRO-H is thin-foil, multi-nested conical optics as well as Suzaku XRT. To reflect hard X-rays efficiently, reflector surfaces are coated with depth-graded Pt/C multilayer. Reflectors are fabricated by the epoxy-replication method. Currently, we have finished the preparation of mirror production facility at Nagoya University, and started test production of reflectors for HXT. The selected 22 pairs of multilayer reflectors have been characterized at the SPring-8 beamline BL20B2.

The current status of the reflector production for ASTRO-H/HXT

Japans 6th X-ray satellite mission ASTRO-H, which is planed to be launched in the fiscal year 2013, will carry two hard X-ray telescopes (HXT) using depth-graded multilayer reflectors which provide us the capability of hard X-ray imaging observation up to 80 keV. ASTRO-H/HXT is the light-weight hard X-ray telescope using Pt/C depth-graded multilayer and high-throughput thin-foil optics. The basic technology for fabricating ASTROH /HXT has been established through the balloon borne experiments, InFOCμS and SUMIT mission. The HXT consists of about 1300 foil reflectors of which a size of the 200 mm mirror length and the diameter range of 120-450 mm which is much larger that those for the balloon borne experiments. To clear the requirements of the angular resolution and the effective photon collecting area for ASTRO-H/HXT, we should produce twice the total number of reflectors and select them. Therefore we need to produce more than 5000 foil reflectors for the two flight telescopes. The installation of the production line and optical evaluation system dedicated to the ASTRO-H/HXT has been almost done. We are testing and improving the production line through productions of several sizes of reflectors. The mass production of the reflectors for the flight model is scheduled to start from July 2010.

The Gamma-ray Cherenkov Telescope for the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) is a forthcoming ground-based observatory for very-high-energy gamma rays. CTA will consist of two arrays of imaging atmospheric Cherenkov telescopes in the Northern and Southern hemispheres, and will combine telescopes of different types to achieve unprecedented performance and energy coverage. The Gamma-ray Cherenkov Telescope (GCT) is one of the small-sized telescopes proposed for CTA to explore the energy range from a few TeV to hundreds of TeV with a field of view ≳ 8° and angular resolution of a few arcminutes. The GCT design features dual-mirror Schwarzschild-Couder optics and a compact camera based on densely-pixelated photodetectors as well as custom electronics. In this contribution we provide an overview of the GCT project with focus on prototype development and testing that is currently ongoing. We present results obtained during the first on-telescope campaign in late 2015 at the Observatoire de Paris-Meudon, during which we recorded the first Cherenkov ima...

The Gamma-ray Cherenkov Telescope, an end-to end Schwarzschild-Couder telescope prototype proposed for the Cherenkov Telescope Array

The GCT (Gamma-ray Cherenkov Telescope) is a dual-mirror prototype of Small-Sized-Telescopes proposed for the Cherenkov Telescope Array (CTA) and made by an Australian-Dutch-French-German-Indian-Japanese-UK-US consortium. The integration of this end-to-end telescope was achieved in 2015. On-site tests and measurements of the first Cherenkov images on the night sky began on November 2015. This contribution describes the telescope and plans for the pre-production and a large scale production within CTA.

Vibration properties of mirror foils for hard x-ray telescope onboard satellite

ASTRO-H is a next version of Japanese X=ray astronomy satellite for lunch in 2014. The hard X-rray telescope (HXT) on board the satellite has a cylindrical mirror housing which contains reflection circular mirror foils. In the present paper, vibration properties of the mirror foils installed in the HXT on-board a satellite were investigated. Vibration tests and FEM analysis of mirror foils installed in the part model of HXT were conducted. From the experimental results, it appeared that the mirror had resonant frequenxcies at 64, 73 and 118Hz. The modal shapes of 64 and 73Hz peaks shhoed that the maximum amplitude appeared at edges of the foil. On the other hand, vibration amplitude became maximum at the center in the modal shape of 118 Hz peak. In addition, it appeared that the first peak of the edge mode decreased with increasing acceleration while the second peak had weak dependency on acceleration. These vibration behaviours are thought to be governed degree of constraint of the connections between the foil and alignment bars.

The current status of reflector production and hard x-ray characterization for ASTRO-H/HXT

Japans sixth X-ray satellite mission ASTRO-H is planned to be launched in 2014. Hard X-ray Telescope (HXT) to cover hard X-rays up to 80 keV is thin-foil, multi-nested conical optics with depth-graded Pt/C multilayer. The mass production of the reflectors for the flight model has been going on since August 2010. We have introduced a new screening method for replication mandrels with optical imagers. In addition, we have adopted a new replication mandrel which consists of glass tube coated with thin glass sheet for large size mandrels. The selected 212 pairs (95 pairs (segment 1), 59 pairs (segment 2), 58 pairs (segment 3)) of multilayer mirror have been characterized at a large synchrotron radiation facility, Spring-8 beamline BL20B2. We present the current status of reflector production and hard X-ray characterization for HXT.