照相透镜重镀透漠及使用情况

介绍了云南天文台太阳光谱仪１９８８年进行的重镀１１块照相透镜增透膜以及镀膜后的使用情况。重镀增透膜前照相透镜的透过率已降低到７７％～９８％。相对于镀膜之前的透过率数值提高１４％～２６％,照相露光时间缩短１倍左右。     

刍议双筒望远镜（二）

双筒中最重要的镀膜当属光学元器件表面的各类增透模（antireflective coatings,图2．14）。如果不镀增透膜,即使光线垂直入射（法向入射）也有约4％的光线被反射损失,那些斜射光线的损失就更多了。利用镀膜的干涉效应,光谱中很宽一段区间的光波的表面反射可降至1．5名以下。通常在510～550nm范围内选择—特定波长,镀膜对这一波长的光有最好的增透性。膜的厚度为波长的1／4。     

CCD蓝敏技术

Ｃ Ｃ Ｄ 用于天文领域已经有近２０ａ （ 年） 的历史, 随着 Ｃ Ｃ Ｄ 技术的发展, 作为重要参数之一的量子效率也得到极大提高, 已经有许多效率在蓝端超过９０ ％ 的芯片应用于天文观测。本文介绍了提高 Ｃ Ｃ Ｄ 蓝端量子效率的多种方法, 包括电极减薄、 Ｌｕｍｏｇｅｎ 镀膜、 Ｃ Ｃ Ｄ 减薄、紫外预照、电子预注入和增透膜等技术等等。可以看到, 采用 Ｃ Ｃ Ｄ 减薄、电荷注入和选择合适的增透膜可以使量子效率接近１００ ％     

CCD蓝敏技术

ＣＣＤ用于文领域已经有近２０ａ（年）的历史,随着ＣＣＤ技术的发展,作为重要参数之一的量子效率也得到极大提高,已经有许多效率在蓝端超过９０％的芯片应用于天文观测。本文介绍了提高ＣＣＤ蓝端量子效率的多种方法,包括电极减薄,Ｌｕｍｏｇｅｎ镀膜等等。可以看到,采用ＣＣＤ减薄、电荷注入和选择合适的增透膜可以使量子效率接近１００％。     

2.4米望远镜主镜镀膜工艺的研究

利用国内首个自上向下热蒸发反射膜的大型镀膜机ZZS3200,开展了2.4 m望远镜主镜镀膜工艺的研究。从镀膜的环境控制,镀膜机蒸发源布置,保护膜的选择,旧膜脱膜等方面出发,探索一种适合2.4 m望远镜主镜的镀膜工艺流程,并依此完成2.4 m望远镜主镜镀带MgF2保护的铝反射膜工作。陪镀片检测表明,铝膜膜厚极大极小值差43 nm,主镜反射膜在350~1 100 nm范围内平均反射率87.16%,经2.4 m望远镜实测,镀膜完成后极限星等不低于23.5 mag,比镀膜前约提高1 mag。2013年12月17日,在2.4 m望远镜上,利用终端云南天文台暗弱天体分光及成像仪(Yunnan Faint-Object Spectrograph and Camera,YFOSC),使用棱栅Grism3分光,对超新星SN 2011fe(V波段19.5 mag)成功进行光谱观测。30 min单幅曝光,获得暗于19 mag天体的光谱,刷新了该类天体在国内观测的新的记录。该目标在光谱观测的同时有相应的测光数据以及测光标准星观测,因此星等测量误差小于0.1 mag,可以用于定量分析。     

LAMOST子镜镀膜研究进展

对大口径光学/红外天文望远镜而言,为保障其稳定高效运行,镜面镀膜是重要的维护环节之一.镀膜质量的好坏直接影响镜面光学反射率的高低,也严重影响到天文望远镜的成像质量、观测效率.国家重大科技基础设施—大天区面积多目标光纤光谱天文望远镜(Large Sky Area Multi-Object Fiber Spectroscopic Telescope, LAMOST,又名郭守敬望远镜)自2009年6月通过国家竣工验收并逐步投入巡天观测,目前已进入第2个5 yr巡天计划阶段,取得近两千万的光谱产出和大批高显示度的科学成果. LAMOST共拥有24块施密特改正镜子镜和37块球面主镜子镜,为了确保在野外恶劣观测环境下镜面反射率维持在较高水平,每年要对大批子镜进行镀膜.主要介绍了镀膜需求、镀膜设备,并基于大量实验和多年的完善探索出一套可行的镀膜工艺流程,确保了LAMOST子镜极高的镀膜质量.镀膜后子镜平均反射率高达90%以上,满足了LAMOST光谱巡天的镜面反射率要求.     

一米望远镜主镜清洗情况报告

一九七九年云南天文台从民主德国引进的一米RCC望远镜自使用以来已历七载。主镜面被尘埃覆盖,反光率大大降低,严重影响使用效果。由于云南天文台尚未建立起一米镜的镀膜设备,重新镀膜的工作必须到北京或上海等地才能进行。将主镜拆下,长途跋涉,费时费财,影响使用,又极不安全。为此,考虑先进行一次清洗,如成功了,可继续工作一段时间。     

可调Lyot双折射滤光器积分透过率守恒的严格证明及一种主带外总光量的测定方法

本文求出了Lyot滤光器透过率函数的原函数,进而导出了计算Lyot滤光器积分透过率的公式,求出了当滤光器的级数趋向于无穷时主带积分透过率占全带积分透过率比的极限值,并对胡岳风、艾国祥发现的可调Lyot双折射滤光器积分透过率守恒,给出了分析证明。最后,本文还提出了一种滤光器主带外总光量的测定方法。     

业余天文摄影的基础知识（3）──照相底片的敏化

业余天文摄影的基础知识（３）──照相底片的敏化蓝松竹对于照相底片，量子效率是指产生一个变黑颗粒所需的入射光子的平均数。当光入射到乳胶上时，一部分被反射，另一部分透射过去，大约只有１０％的光子被乳胶吸收，研究表明，要产生一个可显影的颗粒需吸收１０个光子...     

在各类反射望远镜系统中设计改正透镜的初步讨论

本文讨论在反射望远镜系统中不限制主镜、副镜的表面形状,加入改正透镜后怎样达到同时消去球差、彗差、象散以及场曲的效果,以提高成象的光学质量.一、改正透镜在主焦点系统中的应用1.改正透镜在经典的抛物面主镜主焦点系统中的应用为了提高抛物面反射镜轴外象点的光学质量,罗斯(F.E.Ross)提出可以在焦面以前     

A new technique of observing the magnetic field of solar active regions

By fitting a new type of polarization detector after the entrance slit of a solar spectrograph, the two dimensional magnetic field of solar active regions can be obtained. Not only the field intensity, but also the longitudinal map is obtained quickly. The simultaneous observation of a few lines will also provide data on the structure of the magnetic tubes etc.     

1米太阳望远镜光谱仪像旋转及消旋控制

光谱仪是1 m太阳望远镜的主要终端设备之一,该望远镜采用地平式的机架结构和修正的格里高利光学系统。在望远镜跟踪太阳时,由于地平式望远镜的自身运动特点和光学系统中平面反射镜的存在,其光谱仪狭缝所在平面上的太阳像随时间绕主光轴旋转,因此光谱仪必须进行消旋才能正常工作。首先深入研究了光谱仪狭缝平面上像的旋转变化,分析其旋转范围、速度和加速度随时角变化的特性,然后根据光谱仪消旋精度并结合像的旋转特性提出伺服系统位置检测和驱动电机的主要性能指标,最后给出光谱仪消旋伺服控制方案。     

太阳光谱仪用探测器的研究

观测太阳光谱所使用的探测器,在选型与使用上有其特殊性。结合云南天文台太阳光谱仪,首先建立了太阳光谱仪分光流量的计算机模型,并通过观测实验对该模型进行了检验。利用该模型计算了云南天文台太阳光谱仪各可见光及近红外波段的太阳光谱分光流量,在此基础上,详细讨论了太阳光谱仪用探测器的选型方案,以及观测中的注意要点。     

The use of a laser beam for investigating the instrumental profile of a double-pass solar spectrograph

Some peculiarities of the use of a laser for the determination of the instrumental profile of the high-resolution spectrograph have been described. The results of the investigation of the instrumental profile of the Kiev-Golosejevo double-pass solar spectrograph are presented in graphs.The influence of the width of the slits of the double-pass spectrograph upon the main features of its instrumental profile is discussed briefly.     

Spectroscopic Coronal Observations During the Total Solar Eclipse of 11 July 2010

The flash spectra of the solar chromosphere and corona were measured with a slitless spectrograph before, after, and during the totality of the solar eclipse of 11 July 2010, at Easter Island, Chile. This eclipse took place at the beginning of Solar Cycle 24, after an extended minimum of solar activity. The spectra taken during the eclipse show a different intensity ratio of the red and green coronal lines compared with those taken during the total solar eclipse of 1 August 2008, which took place toward the end of Solar Cycle 23. The characteristic coronal emission line of forbidden Fe xiv (5303 Å) was observed on the east and west solar limbs in four areas relatively symmetrically located with respect to the solar rotation axis. Subtraction of the continuum flash-spectrum background led to the identification of several extremely weak emission lines, including forbidden Ca xv (5694 Å), which is normally detected only in regions of very high excitation, e.g., during flares or above large sunspots. The height of the chromosphere was measured spectrophotometrically, using spectral lines from light elements and compared with the equivalent height of the lower chromosphere measured using spectral lines from heavy elements.     

关于摄谱仪中畸象系统的若干讨论

本文讨论了摄谱仪中若干畸象系统,它们的作用是缩放入射狭缝的象单在高或宽的方向的尺寸,这等效于在狭缝前、后单在子午面内或弧矢面(色散方向面)内改变光束的孔径角,也等效于准直光束单在子午面或弧矢面内缩放光束宽度,在讨论中指出了准直畸象系统优于非准直畸象系统。 在着重讨论和分析准直畸象系统的不同形式时,我们提出了棱镜系统,它具有许多优点,是最为可行的方案。     

MACS for Global measurement of the Solar wind velocity and the Thermal electron temperature during the Total solar eclipse on 11 August 1999

MACS for Multi-Aperture Coronal Spectrometer is a fiber-optic-based spectrograph designed and used to perform global measurement of the solar wind velocity and the thermal electron temperature of the solar corona during the total solar eclipse on 11 August 1999. The motivation for the construction of MACS was provided by the theory formulated by Cram (1976) for the formation of the K-coronal spectrum and a method for determining the radial profile of the thermal electron temperature of the solar corona. Based on this theory a subsequent application was carried out by Ichimoto et al. (1996) using a slit-based spectroscopic study during the total solar eclipse on 3 November 1994. We have modified Cram's theory to incorporate the role of the solar wind velocity in the formation of the K-corona and have identified wind and temperature sensitive intensity ratios. Instead of a slit-based spectrograph MACS consists of twenty fiber optic tips placed at the focal plane of the telescope and positioned to see different radii and latitudes of the solar corona. Another fiber is placed at the center of the frame and uses the lunar shadow for a measure of the background signal. The other ends of the fibers are vertically aligned and placed at the primary focus of the collimating lens of the spectrograph thus providing simultaneous spectra from all of the fibers. In this first paper (Paper I) we describe our instrument and the obtained coronal spectra. The final and complete results will be presented in Paper II (Reginald and Davila, 2000).     

Aspects of the zero level problem of solar magnetographs

The zero level problem of solar magnetographs is particularly important for observations of large-scale magnetic fields on the Sun. Experiments conducted at the STOP telescope of the Sayan observatory show that, in addition to adjustment errors of the polarization analyzer and the spectrograph focusing, spurious signals of the magnetograph are caused by polarization effects in optical components preceding the polarization analyzer and aberration errors of the spectrograph.     

Initial Results of the Ichon Solar Radio Spectrograph

A new solar radio spectrograph to observe solar radio bursts has been installed at the Ichon branch of the Radio Research Laboratory, Ministry of Information and Communication, Korea. The spectrograph consists of three different antennas to sweep a wide band of frequencies in the range of 30 MHz ∼ 2500 MHz. Its daily operation is fully automated and typical examples of solar radio bursts have been successfully observed. In this paper we describe briefly its hardware and data processing methods. Then we present coronal shock speeds estimated for 34 type II bursts from May 1998 to November 2000 and compare them with those from other observatories. We also present the close relationship between onset time of type II bursts and X-ray flares as well as their associations with coronal mass ejections.     

太阳活动区磁场观测的一种新方法

在太阳活动区的物理研究中,特别是在二维动力学光谱分析中,迫切需要相应活动区的磁图资料。本文介绍了在太阳光谱仪的入射狭缝后安装一种新型偏振器进行活动区二维磁场观测的新方法。这种方法不仅能获得日面上任一点的磁场强度,且可快速获得活动区的纵向场磁图。除此之外,还可利用多条谱线的同时观测,获得有关磁力线管结构等方面的资料。