共查询到20条相似文献,搜索用时 15 毫秒
1.
H. Rotzinger J. Adams S. R. Bandler J. Beyer H. Eguchi E. Figueroa-Feliciano W. Hsieh G. M. Seidel T. Stevenson 《Journal of Low Temperature Physics》2008,151(1-2):351-356
We have been developing array technology for fabricating magnetic calorimeters for X-ray astronomy. The magnetization change
in each pixel of the paramagnetic sensor material due to the heat input of an absorbed X-ray is sensed by a meander shaped
coil. With this geometry it is possible to obtain excellent energy sensitivity, low magnetic cross-talk and large format arrays
fabricated on wafers that are separate from the SQUID read-out. A magnetic bias field for each pixel is generated by the use
of a persistent current that is stored. We report on the results from our prototype arrays, which are coupled to low noise
DC-SQUIDs. The first test results are presented and the sensitivity is compared with calculations. 相似文献
2.
Rubina Sultan B. L. Zink K. D. Irwin G. C. Hilton J. N. Ullom L. R. Vale 《Journal of Low Temperature Physics》2008,151(1-2):363-368
Metallic magnetic calorimeters, where deposited energy is detected by measuring a temperature-dependent magnetization with
a low-noise SQUID, remain a promising potential route to X-ray spectrometers with energy resolution approaching 1 eV. In this
paper we describe our recent work toward array-compatible, high-resolution MMCs fabricated entirely using thin-film techniques.
We describe a meander-style pickup loop designed for good coupling to high-efficiency, low noise SQUIDs, as well as considering
various routes to a thin-film paramagnetic sensor. We also briefly overview the most promising technology for multiplexing
arrays of non-dissipative metallic magnetic calorimeters.
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3.
Kosuke Sato Akihiro Tsuchiya Tai Oshima Noriko Y. Yamasaki Toshimitsu Morooka 《Journal of Low Temperature Physics》2008,151(1-2):345-350
We report on the performance of two types of SQUID gradiometers developed for the readout of magnetic calorimeters. Our previously
developed low dissipation SQUID gradiometer optimized for low temperature operation has demonstrated the flux noise level
of
under a magnetic field of 2.5 mT and 150 mK. With a cylindrical Au:Er paramagnetic sensor mounted inside the octagonal pickup
washer of the SQUID gradiometer, we succeeded in detecting X-ray signals. However, our achieved energy resolution was 47.2±2.1 eV
at 5.9 keV limited by the high operating temperature of 150 mK and by a magnetic field, small for that temperature, due to
the limited critical current of the field coils. Based on these results, we fabricated new arrays of SQUID gradiometer by
tuning the line width and the number of turns of the field coils and shunt resistance to realize a lower noise level and a
larger magnetic field. Furthermore, arrays of SQUID gradiometer with meander patterned pickup washer was fabricated which
provides a stronger coupling between the paramagnetic sensor and the pickup washer, and a larger magnetic field at the sensor.
相似文献
4.
W. S. Yoon G. B. Kim H. J. Lee J. Y. Lee J. H. Lee Y. S. Jang S. J. Lee M. K. Lee Y. H. Kim 《Journal of Low Temperature Physics》2014,176(5-6):644-649
We present a detailed report on the fabrication process of a metallic magnetic calorimeter (MMC). The MMC is configured in a planar geometry with a meander-shaped pickup coil covered with a Au:Er temperature sensor layer. The meander coil is used to apply a magnetic field to magnetize the erbium ions and to measure the magnetization change of the spin system. The MMC is designed to have a large area (1 mm \(^2\) ) and 3 \(\upmu \) m thickness Au:Er layer, which is suited for large metal absorbers with a few nJ/K heat capacity in radionuclide analysis applications. The completed devices are used in alpha and Q spectrometries. 相似文献
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H. Rotzinger M. Linck A. Burck M. Rodrigues M. Loidl E. Leblanc L. Fleischmann A. Fleischmann C. Enss 《Journal of Low Temperature Physics》2008,151(3-4):1087-1093
Absolute activity measurements of alpha, beta and gamma emitting radioactive sources are important in numerous fields such
as therapeutic radiology and the characterization of nuclear waste. Conventional ionization and liquid scintillation detectors,
which are commonly used for these applications, have an energy dependent quantum efficiency and severe limitations in energy
resolution. As a novel alternative we have developed a detector based on a metallic magnetic calorimeter (MMC) with a gold
absorber that covers the full solid angle of 4π around the radioactive source. Deposition of energy in the absorber causes a temperature rise and results in a change of
magnetization of a parametric Au:Er sensor, which can be measured by a low-noise high-bandwidth dc-SQUID. The detector has
equal sensitivity for beta and gamma radiation. In this paper we describe a detector which has a deviation from linear behavior
for energies up to 700 keV of smaller than 0.5% and an overall quantum efficiency for beta particles in this energy range
close to unity. We show the data of our experiments measuring the decay of 36Cl and compare the results to the theoretically expected spectrum for this second order forbidden non-unique β-decay. We discuss the observed contributions to noise, the quantum efficiency and the achieved energy resolution. 相似文献
7.
G. B. Kim S. Choi Y. S. Jang H. J. Kim Y. H. Kim V. V. Kobychev H. J. Lee J. H. Lee J. Y. Lee M. K. Lee S. J. Lee W. S. Yoon 《Journal of Low Temperature Physics》2014,176(5-6):637-643
We established a simple thermal model of the heat flow in a large crystal detector designed for a neutrinoless double beta decay experiment. The detector is composed of a CaMoO \(_{4}\) crystal and a metallic magnetic calorimeter (MMC). The thermal connection between the absorber and the sensor consists of a gold film evaporated on the crystal surface and gold bonding wires attached to this film and the MMC sensor. The model describes athermal and thermal processes of heat flow to the gold film. A successive experiment based on optimization calculations of the area and thickness of the gold film showed a significant improvement in the size and rise-time of the measured signals. 相似文献
8.
C. A. Kilbourne S. R. Bandler A.-D. Brown J. A. Chervenak E. Figueroa-Feliciano F. Finkbeiner N. Iyomoto R. L. Kelley F. S. Porter S. J. Smith 《Journal of Low Temperature Physics》2008,151(1-2):223-228
We are developing arrays of superconducting transition-edge sensors (TES) for imaging X-ray spectroscopy telescopes such as
the XMS on Constellation-X. While our primary focus has been on arrays that meet the XMS requirements (of which, foremost,
are an energy resolution of 2.5 eV at 6 keV and a band pass from ∼0.3 keV to 12 keV), we are also beginning to investigate
other optimizations that might be used to extend the XMS capabilities. In one of these optimizations, improved resolution
below 1 keV is achieved by reducing the heat capacity. These low-energy pixels can be added to an array with broadband response
either as a separate array or interspersed, depending on other factors that include telescope design and science requirements.
To explore optimizations for higher count rates, we are also optimizing the design and operating temperature of pixels that
are coupled to a solid substrate. We present analysis of the preliminary performance of such variations.
This research was supported in part by appointments (A.-D. Brown and S.J. Smith) to the NASA Postdoctoral Program at Goddard
Space Flight Center, administered by Oak Ridge Associated Universities through a contract with NASA. 相似文献
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10.
多阳极微通道阵列(MAMA)探测器及其应用 总被引:2,自引:0,他引:2
一种全新的可用于二维光子计数的真空成像器件--多阳极微通道阵列(multi-anode microchannel array简称MAMA)探测器,能探测单个光子的位置信息.本文详细阐述了该探测器的结构、工作原理,并将已研制成功的MAMA探测器的设计考虑及其应用进行了扼要的介绍. 相似文献
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介绍了软X射线Bragg Fresnel光学元件的特点 ,并以磁控溅射法制备多层膜 ,再采用光学全息方法在涂有光刻胶的多层膜表面上形成波带片图形 ,通过显影、离子束刻蚀完成元件的制作 相似文献
13.
M. H. Carpenter S. Friedrich J. A. Hall J. Harris R. Cantor 《Journal of Low Temperature Physics》2014,176(3-4):222-227
We are developing a cryogen-free Ta-based superconducting tunnel junction (STJ) detector for soft X-ray spectroscopy at synchrotrons. With an energy resolution 10 times higher than conventional solid-state X-ray detectors and count-rate capabilities above 5 kHz/pixel, STJ detectors offer potentially increased sensitivity for fluorescence-yield X-ray absorption spectroscopy (FY-XAS). We have developed 36-pixel arrays of 208 \(\times \) 208 \(\upmu \) m Ta STJs with an energy resolution of \(\sim \) 9 eV FWHM at the 525 eV oxygen K line. Compared to earlier Nb-based STJs, Ta-STJs offer improved energy resolution and absorption efficiency and extend the operating range to several keV. Here we describe the integration of the 36-pixel arrays into a cryogen-free, user-friendly X-ray spectrometer. A computer-controlled adiabatic demagnetization refrigerator coupled to a two-stage pulse tube refrigerator allows operation below 100 mK. The detector chip is located at the end of a 42 cm shielded snout for insertion into the analysis chamber. The system is currently being commissioned at the Advanced Light Source synchrotron. 相似文献
14.
D. McCammon K. Barger D. E. Brandl R. P. Brekosky S. G. Crowder J. D. Gygax R. L. Kelley C. A. Kilbourne M. A. Lindeman F. S. Porter L. E. Rocks A. E. Szymkowiak 《Journal of Low Temperature Physics》2008,151(3-4):715-720
We have developed a new calorimeter array to increase our collecting area by a factor of four. The 6×6 pixel device has a
total area of 144 mm2, making it one of the largest X-ray microcalorimeter arrays yet constructed. A relatively thin high-z absorber consisting
of a 0.7 μm HgTe layer supported on 15 μm high-purity silicon provides good efficiency up to photon energies of 1.5 keV. The
heat capacity of this composite is low enough to obtain an energy resolution of ∼6 eV FWHM on the 2 mm×2 mm pixels when operated
at a base temperature of 50 mK. The infrared blocking filters have also been improved. Room temperature radiation must be
attenuated by about 9 orders of magnitude between 2 μm and 2 cm to avoid having photon shot noise dominate the detectornoise.
Accomplishing this while maintaining a high transmission for very soft X-rays that can penetrate only a few μg cm−2 is a problem common to all soft X-ray calorimeters that observe external targets. We are constructing monolithic silicon
two-layer support meshes with a 350 μm pitch front layer on a 5 mm pitch backing layer. These are 98% open and have >95% effective
transmission over a 60° field of view, while providing robust support for 38 mm diameter filters consisting of 20 nm of aluminum
on 50 nm of polyimide. Five of these filters in series provide the necessary infrared attenuation. Integral deicing heaters
are ion implanted in the fine mesh to remove contamination when necessary.
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为了研究一维钴铁氧体纳米管阵列的磁学性质,应用氧化铝模板具有的约束作用和毛细管作用,结合溶胶凝胶技术合成了钴铁氧体纳米管阵列.在140℃条件下,通过包含Fe(AO)3和Co(AO)2(物质的量之比为2∶1)的柠檬酸和乙二醇混合溶液(物质的量之比为1∶4)酯化反应得到溶胶.将氧化铝模板浸入溶胶几次后取出,取出充满溶胶的氧化铝模板,在大气气氛中,以0.6℃/min~5℃/min的升温速度将样品由室温升温至500℃,保温8 h.结果表明,在控制Fe3+离子浓度的条件下也可以合成钴铁氧体纳米线(Fe3+离子浓度大于1 mol/L)和"竹节"型纳米管(Fe3+离子浓度介于0.5 mol/L~1.0 mol/L),但重点进行了其纳米管阵列(Fe3+离子浓度小于0.5 mol/L)合成和磁学性能测试.透射电子显微镜(TEM)、高分辨电镜(HRTEM)的观察以及粉末X光衍射(XRD)测试结果表明纳米管组成为多晶结构.纳米管的直径取决于氧化铝模板的孔径,大约为200 nm,其长度约几个微米.应用样品振动磁强计对样品磁性进行了表征,结果表明纳米管阵列未表现出方向特性,矫顽力随着升温速率的降低而升高,在0.6℃/min的升温速率时,矫顽力达到最高的1 445 kOe,简单讨论了其形成原因. 相似文献
17.
《Nanotechnology, IEEE Transactions on》2008,7(3):251-255
18.
Steven W. Leman Paul L. Brink Blas Cabrera Astrid Tomada Betty Young Dennis S. Martínez-Galarce 《Journal of Low Temperature Physics》2008,151(1-2):40-45
We continue our development of a phonon-mediated distributed-TES X-ray detector. X-rays are absorbed in a large silicon or
germanium crystal, and the energy is read out by four distributed TESs. This design takes advantage of existing TES technology
while overcoming the difficulties of designing spatially large arrays. In this paper, we discuss three detector designs. First,
a silicon detector with 220 μm deep trenches through a 350 μm crystal. Second, a germanium detector with 275 μm deep trenches
through a 550 μm crystal. Finally another silicon detector with 330 μm deep trenches through a 350 μm crystal. We discuss
energy loss mechanisms in the detector and propose a reason for the energy resolution that we observe.
相似文献
19.
M. Higano A. Miyagawa K. Saigou H. Masuda H. Miyashita 《International Journal of Thermophysics》1999,20(1):207-215
The specific heat capacity of magnetic fluids was measured using a heat-flux-type differential scanning calorimeter (DSC). Magnetic fluids which contain 10 to 43 wt% ultrafine magnetite (Fe3O4) particles dispersed with surfactants in water or kerosene were used. The DSC was operated with the optimum heating rate (10 K·min–1) and with equal heat capacities of sample and standard materials in the temperature range, 295 to 345 K. Synthetic sapphire (-Al2O3) was used as the standard reference material, and the sample pan was made from aluminum. The differences between the measured specific heat capacity values of pure water and pure copper and the recommended values were within ±3 and ±1%, respectively. The specific heat capacity data of magnetic fluids showed weak temperature dependence, but strong concentration dependence. The measured values of specific heat capacity of magnetic fluids were compared with calculated values using a mixing rule. 相似文献
20.
采用微波等离子体化学气相沉积(MPCVD)方法制备了100μm米厚高质量(100)定向金刚石薄膜. 利用(100)定向金刚石薄膜成功制备了α粒子探测器, -100V偏压下电荷平均收集效率为37.7%, 最大的电荷收集效率达到60%以上. 在此基础上, 通过在α粒子探测器条状电极面蒸镀一层合适厚度的硼(10B)膜转化层, 成功研制了金刚石中子探测器. 镀硼之后探测器对中子有明显的响应, 在1V/μm电场下, 对252Cf中子的能量分辨率达到9.3%,探测效率达到1.67%. 同时还研究了电场强度和硼(10B)层厚度对器件探测效率的影响规律. 在厚度<1.5μm时, 随着厚度的增加, 探测效率上升, 当厚度>1.5μm时, 探测效率下降. 相似文献