The construction of a prototype Schwarzschild-Couder telescope (pSCT) started in early June 2015 at the Fred Lawrence Whipple Observatory in Southern Arizona, as a candidate medium-sized telescope for the Cherenkov Telescope Array (CTA). Compared to current Davies-Cotton telescopes, this novel instrument with an aplanatic two-mirror optical system will offer a wider field-of-view and improved angular resolution. In addition, the reduced plate scale of the camera allows the use of highly-integrated photon detectors such as silicon photo multipliers. As part of CTA, this design has the potential to greatly improve the performance of the next generation ground-based observatory for very high-energy (E>60 GeV) gamma-ray astronomy. In this contribution we present the design and performance of both optical and alignment systems of the pSCT.
The Cherenkov Telescope Array (CTA) is the next generation very high-energy gamma-ray observatory, with at least 10
times higher sensitivity than current instruments. CTA will comprise several tens of Imaging Atmospheric Cherenkov
Telescopes (IACTs) operated in array-mode and divided into three size classes: large, medium and small telescopes. The
total reflective surface could be up to 10,000 m<sup>2</sup> requiring unprecedented technological efforts. The properties of the
reflector directly influence the telescope performance and thus constitute a fundamental ingredient to improve and
maintain the sensitivity. The R&D status of lightweight, reliable and cost-effective mirror facets for the CTA telescope
reflectors for the different classes of telescopes is reviewed in this paper.
The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for very high-energy (E>100 GeV) gamma-ray astronomy. It will integrate several tens of imaging atmospheric Cherenkov telescopes (IACTs) with different apertures into a single astronomical instrument. The US part of the CTA collaboration has proposed and is developing a novel IACT design with a Schwarzschild-Couder (SC) aplanatic two-mirror optical system. In comparison with the traditional single mirror Davies-Cotton IACT the SC telescope, by design, can accommodate a wider field-of-view, with significantly improved imaging resolution. In addition, the reduced plate scale of an SC telescope makes it compatible with highly integrated cameras assembled from silicon photo multipliers. In this submission we report on the status of the development of the SC optical system, which is part of the e ort to construct a full-scale prototype telescope of this type at the Fred Lawrence Whipple Observatory in southern Arizona.
The laser cutting of color metals and alloys by a thickness more than 2 mm has significant difficulties due to high reflective ability and large thermal conduction. We made it possible to raise energy efficiency and quality of laser cutting by using a laser processing system (LPS) consisting both of the YAG:Nd laser with passive Q-switching on base of LiF:F<SUB>2</SUB><SUP>-</SUP> crystals and the CO<SUB>2</SUB> laser. A distinctive feature of the LPS is that the radiation of different lasers incorporated in a coaxial beam has simultaneously high level of peak power (more than 400 kW in a TEM<SUB>00</SUB> mode) and significant level of average power (up to 800 W in a TEM<SUB>01</SUB> mode of the CO<SUB>2</SUB> laser). The application of combined radiation for cutting of an aluminum alloy of D16 type made it possible to decrease the cutting energy threshold in 1.7 times, to increase depth of treatment from 2 up to 4 mm, and velocity from 0.015 up to 0.7 m/min, and also to eliminate application of absorptive coatings. At cutting of steels the velocity of treatment was doubled, and also an oxygen flow was eliminated from the technological process and replaced by the air. The obtained raise of energy efficiency and quality of cutting is explained by an essential size reducing of a formed penetration channel and by the shifting of a thermal cutting mode from melting to evaporation. The evaluation of interaction efficiency of a combined radiation was produced on the basis of non-stationary thermal-hydrodynamic model of a heating source moving as in the cutting direction, and also into the depth of material.