Observation constraints of the hard X-ray modulation telescope HXMT

The hard X-ray modulation telescope HXMT is a low orbit X-ray space telescope whose main science goals are to accomplish a hard X-ray all sky survey and to study timing and spectral characteristics of X-ray sources. HXMT has three kinds of science instruments: the high energy X-ray detector (HE), the medium energy X-ray detector (ME) and the low energy X-ray detector (LE). The observation schedule of HXMT is a key to achieving the science goal of HXMT, and the analysis of the observation constraints is one of the first tasks in making the observation schedule. This paper analyzes how the observation constraints influence the sky visibility and the visible time distribution of X-ray sources and discusses the schedule strategy with regard to the observation constraints.     

Space solar telescope in soft X-ray and EUV band

In this paper we have reviewed our achievements in soft X-ray and extreme ultraviolet (EUV) optics. Up to now, the research system of soft X-ray and EUV optics has been established, including light sources, detectors, calibrations, optical testing and machining of super smooth mirrors, and fabrications of multilayer film mirrors. Based on our achievements, we have developed two types of solar space telescopes for the soft X-ray and EUV space solar observations. One is an EUV multilayer normal incident telescope array including 4 different operation wavelength telescopes. The operation wavelengths of the EUV telescope are 13.0, 17.1, 19.5 and 30.4 nm. The other is a complex space solar telescope, which is composed of an EUV multilayer normal incident telescope and a soft X-ray grazing incident telescope. The EUV multilayer normal incident telescope stands in the central part of the soft X-ray grazing incident telescope. The normal incident telescope and the grazing incident telescope have a common detector. The different operation wavelengths can be changed by rotating a filter wheel.     

一种复合型空间软X射线--极紫外波段望远镜设计

根据空间对日观测的需要,提出了一种复合型宽波段范围的软X射线———极紫外望远镜的设计方案。该望远镜是把小结构尺寸的卡塞格林型极紫外波段正入射望远镜放置在软X射线波段,并由常用的Wolter Ⅰ型掠入射望远镜的中心部分组成。在软X射线和极紫外波段具有相同的焦距和视场角,共同使用同一个探测器,外形尺寸与相同指标的掠入射型望远镜一致,且在极紫外波段具有较高的角分辨率和光谱分辨率,适合于在空间进行对日观测使用。     

空间引力波探测望远镜初步设计与分析

引力波的直接观测已开启引力波天文学的新篇章,爱因斯坦的百年预言终获证实。空间引力波探测器使得探测0.1 m Hz~1 Hz频段丰富的引力波源成为可能,与地面引力波探测器互为补充,才可实现更加宽广波段的引力波探测,揭开宇宙早期的更多秘密。空间激光干涉引力波探测采用外差干涉测量技术,测量间距百万公里的两自由悬浮测试质量间10 pm量级的变化量。望远镜是激光干涉测量系统的重要组成部分,1 pm的光程稳定性及苛刻的杂散光要求,不同于传统的几何成像望远镜。本文根据空间太极计划任务需求,对望远镜的功能及技术要求进行了分析,并完成了原理样机的初步方案设计,针对百万公里远场波前分布,分析了望远镜系统的敏感性,同时完成了在轨光机热集成仿真,为后面原理样机的研制奠定了技术基础。     

大口径折反式中波红外衍射望远镜系统设计

为实现空间红外望远镜的高分辨率探测,基于Schupmann消色差理论,开展了大口径折反式中波红外衍射望远镜系统的设计及消热差模型研究。设计了口径1 m、F数为2、全视场0.12°、波段3.8 μm～4.2 μm的折反式中波红外衍射望远镜系统,其主镜及校正镜均为平面衍射透镜,中继系统采用卡塞格林折反式结构,再聚焦及三次成像系统均为折射式结构,对系统进行了公差、鬼像及冷反射分析。设计结果表明:在?20 ℃～60 ℃温度下,系统的MTF在16.7 lp/mm范围内均大于0.7,接近衍射极限,且具有100%冷屏效率,公差满足现有加工装配水平;鬼像能量为0.1%,对目标信号的影响较小;冷反射等效温差（NITD）随温度的变化量小于探测器噪声等效温差（NETD）。该系统可为更大口径红外衍射望远镜系统的设计提供参考。     

Data acquisition system for the Baikal-GVD neutrino telescope

The objective of the Baikal-GVD project is the construction of a km³-scale neutrino telescope in Lake Baikal. The Gigaton Volume Detector consists of a large three-dimensional array of photo-multiplier tubes. The first GVD-cluster has been deployed and commissioned in April 2015. The data acquisition system (DAQ) of the detector takes care of the digitization of the photo-multiplier tube signals, data transmission, filtering and storage. The design and the implementation of the data acquisition system are described.     

月基望远镜热设计及热分析

为了利用月球观测地球等离子体层的优势,开展了月基望远镜的研究,并对其进行了热设计和热分析.分析了月基望远镜所处的空间环境.对望远镜各个部分进行了热设计;采用被动热控措施控制望远镜的温度水平,降低空间环境的影响;采用热疏导的方式对探测器进行散热.根据月基望远镜的空间环境、结构特点,以及采取的热控措施,在I-DEAS/TM...     

Status and first results of the ANTARES neutrino telescope

The ANTARES detector is the most sensitive neutrino telescope observing the southern sky and the world’s first particle detector operating in the deep sea. It is installed in the Mediterranean Sea at a depth of 2475 m. As example for the first results, the determination of the atmospheric muon flux is discussed; a fair agreement with previous measurements is found. Furthermore, the results of a search for high-energy events in excess of the atmospheric neutrino flux are reported and significant limits are set on the diffuse cosmic neutrino flux in the multi-TeV to PeV energy range. Using data taken during the construction phase, a first analysis searching for point-like excesses in the neutrino sky distribution has been performed. The resulting sensitivity of ANTARES is reported and compared to measurements of other detectors.     

带有二元光学元件的可见光望远镜设计

本文讨论了可见光常规望远镜的特点及存在的问题，论述了在望远镜系统中加入二元光学元件（ＢＯＥ）的优点和设计方法。通过具体设计实例表明：混合型望远镜系统与光学性能与基本相同的常规望远镜相比，元件数目减少，且所有元件均使用Ｋ９玻璃，系统重量变轻，系统的结构简化。     

Method for reconstructing primary parameters of events in a water Cherenkov telescope of the SuperKamiokande type

Methods for reconstructing the energy, event type, direction of motion, and injection point for electrons and muons in a water Cherenkov neutrino telescope similar to the SuperKamiokande detector are considered. The limiting resolutions estimated on the basis of an event simulation are compared with the values reported by the SuperKamiokande Collaboration.     

Analysis of telescope array receivers for deep-space inter-planetary optical communication link between Earth and Mars

Optical communication technology shows promising prospects to fulfill the large bandwidth communication requirements of future deep-space exploration missions that are launched by NASA and various other international space agencies. At Earth, a telescope with a large aperture diameter is required to capture very weak optical signals that are transmitted from distant planets and to support large bandwidth communication link. A single large telescope has the limitations of cost, single point failure in case of malfunction, difficulty in manufacturing high quality optics, maintenance, and trouble in providing communication operations when transmitting spacecraft is close to the Sun. An array of relatively smaller-sized telescopes electrically connected to form an aggregate aperture area equivalent to a single large telescope is a viable alternative to a monolithic gigantic aperture. In this paper, we present the design concept and analysis of telescope array receivers for an optical communication link between Earth and Mars. Pulse-position modulation (PPM) is used at the transmitter end and photon-counting detectors along with the direct-detection technique are employed at each telescope element in the array. We also present the optimization of various system parameters, such as detector size (i.e., receiver field of view), PPM slot width, and the PPM order M, to mitigate the atmospheric turbulence and background noise effects, and to maximize the communication system performance. The performance of different array architectures is evaluated through analytical techniques and Monte-Carlo simulations for a broad range of operational scenarios, such as, Earth-Mars conjunction, Earth-Mars opposition, and different background and turbulence conditions. It is shown that the performance of the telescope array-based receiver is equivalent to a single large telescope; and as compared to current RF technology, telescope array-based optical receivers can provide several orders of magnitude greater data rates for deep-space communication with Mars.     

被动无热化切换式长波红外双视场望远镜

 提出切换式双视场光学系统的结构形式,探讨了切换式双视场光学系统的被动无热化设计理论。在此基础上,设计了工作波长为7.7 μm～10.3 μm的被动无热化切换式双视场望远镜。采用衍射面和非球面减少光学元件数量并提高像质,切换式双视场望远镜在-55℃～+70℃全温度带内MTF@18 lp/mm≥0.45。最后对设计结果进行了扩展,给出2个以该结构形式和材料分配为基础的镜头设计结果,结果表明该结构形式和材料分配具有一定的普适性。     

Preliminary results from the TUS ultra-high energy cosmic ray orbital telescope: Registration of low-energy particles passing through the photodetector

The TUS telescope, part of the scientific equipment on board the Lomonosov satellite, is the world’s first orbital detector of ultra-high energy cosmic rays. Preliminary results from analyzing unexpected powerful signals that have been detected from the first days of the telescope’s operation are presented. These signals appear simultaneously in time intervals of around 1 μs in groups of adjacent pixels of the photodetector and form linear track-like sequences. The results from computer simulations using the GEANT4 software and the observed strong latitudinal dependence of the distribution of the events favor the hypothesis that the observed signals result from protons with energies of several hundred MeV to several GeV passing through the photodetector of the TUS telescope.     

硬X射线调制望远镜低能探测器量子效率标定

低能X射线望远镜是硬X射线调制望远镜卫星的主要载荷之一,探测器采用CCD236.探测器的量子效率会影响能谱拟合和绝对流量,有必要对其进行标定.利用~(55)Fe放射源,以硅漂移探测器为标准探测器,标定了CCD236在Mn-K_α(5.899 keV)和Mn-K_β(6.497 keV)能量点处的量子效率,此能段在Fe线附近,对X射线天文观测有重要价值.考虑探测器的分裂事例后,Mn-K_α和Mn-K_β处的量子效率分别为71%和62%.在-95—-30?C工作温度范围内,CCD量子效率与温度无关.利用CCD236的结构及实测的量子效率,不考虑沟阻影响,得到耗尽层厚度为38μm.对CCD236施加不同的电压,其量子效率基本不变,表明其在两相驱动下高低电平的耗尽层厚度相等,进而说明CCD236一直工作在深耗尽状态,其耗尽层到了外延层和衬底层边界,已达最大值.     

光学天文望远镜的足迹

文章以较为轻松的笔调概述了光学天文望远镜400年的发展史.全文分7个部分,内容包括望远镜的诞生、像差和消色差透镜、传统的反射望远镜和折射望远镜、施密特望远镜的作用、当代巨型望远镜的出现、空间望远镜,以及对月基望远镜的憧憬.     

ф300mm卡塞格林望远镜

本文介绍安装于佛山市第一中学的ф３００ｍｍ卡塞格林天文望远镜的总体考虑和光学机械、电器控制系统以及仪器的装校，着重介绍光学装校及其精度。该望远镜是全国中等学校口径最大功能最多的卡塞格林天文反光望远镜。     

A telescope detection system for direct and high resolution spectrometry of intense neutron fields

A high energy- and spatial-resolution telescope detector was designed and constructed for neutron spectrometry of intense neutron fields. The detector is constituted by a plastic scintillator coupled to a monolithic silicon telescope (MST), in turn consisting of a ΔE and an E stage. The scintillator behaves as an “active” recoil-proton converter, since it measures the deposited energy of the recoil-protons generated across. The MST measures the residual energy of recoil-protons downstream of the converter and also discriminates recoil-protons from photons associated to the neutron field. The lay-out of the scintillator/MST system was optimized through an analytical model for selecting the angular range of the scattered protons. The use of unfolding techniques for reconstructing the neutron energy distribution was thus avoided with reasonable uncertainty (about 1.6% in neutron energy) and efficiency (of the order of 10⁻⁶ counts per unit neutron fluence). A semi-empirical procedure was also developed for correcting the non-linearity in light emission from the organic scintillator. The spectrometer was characterized with quasi-monoenergetic and continuous fields of neutrons generated at the CN Van De Graaff accelerator of the INFN-Legnaro National Laboratory, Italy, showing satisfactory agreement with literature data.     

A multilayer ΔE-ER telescope for breakup reactions at energies around the Coulomb barrier

The breakup reactions of weakly-bound nuclei at energies around the Coulomb barrier and the corresponding coupling effect on the other reaction channels are hot topics nowadays. To overcome the difficulty in identifying both heavier and lighter fragments simultaneously, a new kind of ionization-chamber based detector telescope has been designed and manufactured. It consists of a PCB ionization chamber and three different thickness silicon detectors installed inside the chamber, which form a multilayer ΔE-E_R telescope. The working conditions were surveyed by using an α source. An in-beam test experiment shows that the detector has good particle identification for heavy particles like ¹⁷F and ¹⁶O as well as light particles like protons and alpha particles. The measured quasi-elastic scattering angular distribution and the related discussions for ¹⁷F+²⁰⁸Pb are presented.     

Impact of telescope seeing on laser adaptive optics

Atmospheric turbulence in the internal light path of a telescope produces noncommon path phase differences that degrade the image quality of adaptive-optics systems employing laser guide stars. The spatial covariance and rms wavefront errors produced by this effect are derived. It is found that the tilt-removed wavefront error ranges from about 12 nm for a representative 30 m telescope to 59 nm for a 100 m telescope of similar optical design. For adaptive-optics systems that aim to derive tip-tilt information from the laser guide stars the error is considerably larger, ranging from 22 nm for the 30 m telescope to 256 nm for the 100 m telescope. This effect can be a significant impediment to the performance of such systems.     

Spectral calibration of filters and detectors of solar telescope at a wavelength of 13.2 nm for the TESIS project

The telescope at a wavelength of 13.2 nm of the TESIS device of the CORONAS-PHOTON satellite is intended for imaging hot plasma (T ～ 10 MK) of the solar corona. In this paper, calibration of optical elements of the telescope is described. The transmittance of multilayer Zr/Si filters and the sensitivity and radiation resistance of the CCD-array-based detector were measured. The transmittance of filters in the operating wavelength range was 40–50% (for filters of various thicknesses); the spectral dependence of the transmittance was close to the calculated one. The transmittance of filters in the visible region was (1–2) × 10^?6. The detector sensitivity was 0.01–0.1 analog-to-digital units per photon (adu/photon), the radiation resistance was better than 10⁹ rad.