2008.12
About Instruments Today No. 167
Astronomical Instrumentation
The Next Generation Compton Telescope [ 下載 PDF ]
Hsiang-Kuang Chang
Instruments and technology employed in astronomical observations at different wave bands are quite different. This article discusses the detection and imaging of cosmic MeV photons and introduces an on-going project of developing a Compton imaging spectrometer, known as the Nuclear Compton Telescope (NCT) project in the international astronomical community. NCT can achieve unprecedented sensitivity with a compact volume. The technology developed in the NCT project may become the main stream of the next generation Compton telescope. It can also be applied to the field of medical imaging.
Yuan-Tseh Lee Array for Microwave Background Anisotropy [ 下載 PDF ]
Chen Ming-Tang
The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA, hereafter) is an array-type radio telescope. It is consisted of 7-element, 60 cm diameter, millimeter-wave antenna-receivers. The Array is mounted on a 6 meter platform made of reinforced carbon fiber, and supported by a unique hexapod mount. Every antenna is a very sensitive, dual-polarization receiver. It detects RF signal of 86–102 GHz, and of IF frequency 2–18 GHz. To achieve better sensitivity, the Array is using analog correlator, which simultaneously processes a bandwidth of 16 GHz. AMiBA is located on the slow slope of Mauna Loa, Hawaii, USA, with an altitude 3,400 meters. The Array has been dedicated on Oct, 2006 and renamed as the Yuan-Tseh Lee Array for Microwave Background Anisotropy, to appreciate the long-term support in Taiwanese astronomy development from Dr. Lee. By 2008, AMiBA has finished its initial science observations and progressed into the expansion phase to expand the Array from 7 to 13 elements with 1.2-meter dishes.
Frontier Challenges in Astronomical Observations — The Pan-STARRS Project [ 下載 PDF ]
Wen-Ping Chen
Advance in instrumentation in observational astronomy has been leaping — ever increase in the telescope aperture, improved sensitivity and larger focal-plane coverage in the detector technology. This article describes the hardware and software development of Pan-STARRS (Panoramic Survey Telescope And Rapid Response System), a telescope facility for which Taiwan is involved in the scientific operations, together with an elite group from the US, Germany and the UK, to patrol the entire visible sky several times per month by employing wide-field optics, and a CCD camera with 1.4 gigapixels that makes use of an innovative orthogonal transfer technology. Pan-STARRS will be a powerful tool to identify celestial objects variable in position or in brightness, and will revolutionize optical observations in time-domain astrophysics.
The Development of Large Format Infrared Astronomical Cameras [ 下載 PDF ]
Shiang-Yu Wang
Modern astronomical research is closely connected to the technical development of the instrumentation. Especially, the introduction of the solid state detector dramatically changed the astronomical research and leads to the precise quantitative analysis. Furthermore, with the more and more requests for better astronomical images, advanced sensor arrays were developed in the last decade. In this paper, we will introduce the large infrared camera project Taiwan participates. With the projects, the detailed of the astronomical camera will be presented and the requirements and features of the astronomical camera will be compared with the digital cameras for normal applications.
Coded Aperture Mask Technique in Imaging High Energy Astronomical Telescopes [ 下載 PDF ]
Yi Chou
Coded aperture mask technique to image the hard X-ray and γ-ray sky has been adopted to many X-ray telescopes since early 80's. In comparison to X-ray optics for soft X-ray, the telescopes using coded mask technique may have wider bandwidth, larger field of view and effective area. This article introduces the basic principle of coded aperture mask and how to recover the original image with cross correlation method. Its applications to astronomical telescopes, including selection of mask and data reduction, as well as the vantages, limitations and prospects of coded aperture mask telescopes are also discussed.
The Study of Optical Properties for Anisotropic Thin Film [ 下載 PDF ]
Yi-Jun Jen, Ching-Wei Yu, Chia-Feng Lin
The phisweep technique is applied in coating anisotropic films. During the deposition, the periodical sweep of the substrate will improve the fan-out phenomenon. Aluminum (Al) nanorod arrays (NRA) thin film are prepared by oblique angle deposition (OAD). Anisotropic optical properties of the film are measured for polarized lights which the oscillating direction of electric field is perpendicular (S-polarization) and parallel (P-polarization) to the plane of the incidence. The attenuated total reflection (ATR) curves are measured for the prism/NRA/air system. The optical resonances of ATR are interpreted by ray tracing method to find that the P polarized resonance is associated with the surface plasmon resonance. The S polarized resonance occurs because the destructive interference becomes obvious at the oblique incidence. Moreover, the polarization state of the reflected light is modulated by rotating the deposition plane of the anisotropic MgF2 layer in the prism/isotropic film/anisotropic MgF2 film/air system.
Investigation of Extraordinary Transmission in Textured Metal Films Using Nano-Imprinting Machine [ 下載 PDF ]
Shang-Yu Chuang, Hsuen-Li Chen, Shang-Shang Kuo
In this paper, we describe a thermal embossing imprint method, named as 'nano-imprinting in metal' (NIM), for patterning metal films with a variety of profiles. Metal films exhibiting either perforated hole-arrays or corrugated structures with various surface morphologies can be fabricated rapidly. The SPR phenomenon allowed energy coupling to the other side of the textured metal film, causing a dramatic increase in the transmission. As a technique for readily controlling the working wavelength and transmittance, the NIM method has great potential for application in various optoelectronic devices.
The 21st Century Biosensors Developed Status and Prospects [ 下載 PDF ]
Ming-Yu Lin, Vicent Hsiao, Chun-Lun Lin, Cheng-Yun Hsiao, Wen-Yih Chen, Yuh-Shyong Yang
This report describes and discusses the biosensor technologies that will play an important role in the practice of medical diagnostics, drug screening, food industry, agriculture industry, environmental trace analytes detection, and biological warfare in the 21st century. This includes promising technologies for the development of biosensors with advantages of high sensitivity, high specificity, high stability and user friendly. Four technologies will be presented, including rolling circle amplification technology, polysilicon nanowire field-effect transistor, microring resonator, guided-mode resonance transistor.
To Explore A High Magnetic Field Surface Magneto-Optic Effect System and Its Related Key Technology [ 下載 PDF ]
Chiung-Wu Su, Yen-Chu Chang, Ming-Siang Huang, Tsung-Hsuan Tsai
The paper will introduce the development of surface magneto-optic effect technique and how to apply in the ultrahigh vacuum system of author's lab. The magnetic properties such as typical magnetic hysteresis loops can be measured successfully under the field strength reaching as high as ±3200 Oe. We will also discuss the realistic problems about the automatic control of current source, the detection of photo signals, the selection of sample holder and other vacuum components, and photo alignments for the home-made users who want to setup their own device. Besides, authors will show the successful results from the hysteresis loop measurements of Fe/Si samples and observations of the loop variation from the deposition of Co ultrathin films on ZnO (002) crystal surface.
Study for Semiconductor Type Fast Response Ethanol Sensor by Using of CuO-ZnO [ 下載 PDF ]
Ren-Jang Wu, Ming-Ru Yu, Tzu Hsuan Lin, Shin-Lin Hung
A study for detecting ethanol was performed by application of CuO-ZnO materials, high sensor response (S) was got from the adjusting appropriate ratio of CuO and ZnO. By using the theory of resistance variation to ethanol adsorption on surface of sensing material, resistance was transformed to voltage signal and detected. In the of condition 1:1 weight ratio of CuO and ZnO, the sensor response was 2.5 to 1243 ppm ethanol at room working temperature. The response and recovery times were measured as 30 and 25 s, respectively. Composite materials were the active center of CuO-ZnO by studying TPR data. Sensor response was performed with the ethanol concentration be varied from 1200 to 24000 ppm. The sensing materials are promising for the ethanol gas detection in the future.
