Optimisation of design parameters for collimators and pin-holes of bolometer cameras

The total radiation emission profile of fusion experiments is usually determined using the bolometer diagnostic. In order to evaluate the spatially resolved profile, many line integrated measurements are inverted using tomographic reconstruction techniques. Their success depends on a well known and optimised definition of the viewing cones of every line-of-sight. To this aim a set of equations has been derived and put in hierarchical order to define the design parameters for bolometer cameras in fusion experiments. In particular, previous considerations, which focussed on the beam width overlap and light yield optimisation, are extended to explicitly take geometrical boundary conditions imposed by the experimental device into account, with an emphasis on small gap sizes through which viewing cones have to pass through. The equations are derived for both camera types, collimator and pin-hole versions. The results obtained can be used to design bolometer cameras for any fusion device, but in particular also for ITER. An example of such an application is given and implications for the realisation of the optimal design are discussed.     

Modelling of the Surface-Event Identification Mechanism in Ge Detectors Equipped with NbSi Thin Films

A new generation of germanium composite bolometers, equipped with NbSi thin films, has been developed in the framework of the EDELWEISS experiment, presenting impressive surface event identification capabilities and a substantial improvement in the background rejection of heat and ionization detectors. In this work we present a simple thermal model which explain the surface-event identification mechanism via NbSi thin films sensors.      

用液氦致冷的球载远红外光度计

介绍供观测银心和银道面红外辐射用的快速扫描远红外光度计，光度计的主要元件是用液氦致冷的锗测辐射热探测器，本文还介绍了光度计的总体考虑，各部件的结构，定标设备和观测结果。     

国外长波红外焦平面列阵现状

文中介绍了长波工外焦平面列阵的国外进展，这些列阵包括碲镉汞光电二极管、肖特基势垒器件、砷化镓／砷铝镓多量子阱光导体、高温超导体以及室温工作的焦平面列阵，其中非制冷的混合式热释电陶瓷和单片式的微型测辐射热计焦平面列阵已进入批理生产阶段。     

高温超导红外探测器对1—1000μm波段的光谱响应

采用ＹＢａＣｕＯ高温超导薄膜，制成芯片为蛇形的Ｔｃ超导Ｂｏｌｏｍｅｔｅｒ，对１￣１０００μｍ波段的光谱响应进行了测量，本文报道了实际测量结果，表明高温超导红外探测器在红外－毫米波段有应用前景。     

TES Bolometer Array for the APEX-SZ Camera

We will report on the APEX-SZ bolometer camera which houses a 320 element Transition-Edge Sensor (TES) bolometer array designed to survey for galaxy clusters using the 12-meter diameter APEX telescope sited in Chile. Design and fabrication of the TES bolometer array will be discussed, as well as its integration with a frequency-domain SQUID multiplexed readout system. The full configuration of the APEX-SZ camera was deployed in April 2007. A preliminary galaxy cluster map from this deployment will be presented.      

GISMO, a 2 mm Bolometer Camera Optimized for the Study of High Redshift Galaxies

The 2 mm spectral range provides a unique terrestrial window enabling ground based observations of the earliest active dusty galaxies in the universe and thereby allowing a better constraint on the star formation rate in these objects. We have built GISMO (the Goddard-IRAM Superconducting 2-Millimeter Observer), a 2 mm, 128 element superconducting Transition Edge Sensor (TES) based bolometer camera for the IRAM 30 m telescope in Spain. The camera uses an 8×16 planar array of multiplexed TES bolometers, which incorporates our recently designed Backshort Under Grid (BUG) architecture, described elsewhere. The optical design incorporates a 100 mm (4 inches) diameter silicon lens cooled to 4 K, which provides the required fast beam of 0.9 λ/D. With this spatial sampling, GISMO will be very efficient at detecting sources serendipitously in large sky surveys, while the capability for diffraction-limited observations is preserved. With the background limited performance of the detectors, the camera provides significantly greater imaging sensitivity and mapping speed at this wavelength than has previously been possible. The major scientific driver for the instrument is to provide the IRAM 30 m telescope with the capability to rapidly observe galactic and extragalactic dust emission, in particular from high-z Ultra Luminous Infrared Galaxies (ULIRGs) and quasars, even in the summer season. The instrument will fill in the SEDs of high redshift galaxies at the Rayleigh-Jeans part of the dust emission spectrum, even at the highest redshifts. Our source count models predict that GISMO will serendipitously detect one galaxy every four hours on the blank sky, and that one quarter of these galaxies will be at a redshift of z 6.5. We expect to install GISMO at the 30 m telescope in the second half of 2007.      

Antenna-Coupled Bolometer Arrays for Measurement of the Cosmic Microwave Background Polarization

We are building antenna-coupled Transition Edge Sensor bolometer arrays to measure the polarization of the cosmic microwave background. 217 GHz prototype pixels have previously been characterized and showed promising performance (Myers et al. in Appl. Phys. Lett. 86:114103, [2005]). Our design uses a double slot dipole antenna and an integrated microstrip band defining filter. New devices have been tested which include on-chip test structures to improve our understanding of detector performance and guide future development. In parallel with this, large arrays of bolometers based on the prototype pixel design have also been constructed. The array pixels are a heterogeneous mixture of single band pixels at 90 GHz, 150 GHz, and 220 GHz and now incorporate dual-polarization antennas (Chattopadhyay and Zmuidzinas in IEEE Trans. Antennas Propag. 46:736, [1998]). Preliminary results from optical testing of array pixels are presented. These bolometer arrays will be used in the upcoming CMB polarization experiment Polarbear.      

一种用于探测太赫兹信号的测辐射热仪

基于Nb5N6薄膜在室温下具有高达-0.7％ K-1的电阻温度系数,用Nb5N6薄膜结合平面蝴蝶结天线制备了一种可在室温下进行100 GHz信号探测的测辐射热仪.该器件在偏置电流为0.4 mA的条件下,达到的最佳电压响应为-400 V/W,调制频率为200 Hz时等效噪声功率达到1.5 ×10-11 w/(√Hz),调制频率10 kHz以上时等效噪声功率优于9.5×10-12W/(√Hz).     

1×8线阵高温超导远红外热型探测器研制

采用高质量的 YBCO 高温超导薄膜,研制成1×8线阵超导远红外热型探测器。测量了线阵中各单元器件的性能,结果表明:NEP 在10~(-11)WHz~(-1/2),D~*在10~8m·Hz~(1/2)·W~(-1)的范围内。