Development of a high resolution x-ray spectrometer for the National Ignition Facility (NIF)
A high resolution (E/ ΔE = 1200-1800) Bragg crystalx-ray spectrometer is being developed tomeasureplasma parameters in National Ignition Facility experiments. The instrument will be adiagnostic instrument manipulator positioned cassette designed mainly to infer electron density in compressed capsules from Stark broadening of the helium- β (1s2-1s3p) lines of krypton and electron temperature from the relative intensities of dielectronic satellites. Two conically shaped crystals willdiffract and focus (1) the Kr He β complex and (2) the Heα (1s2-1s2p) and Ly α (1s-2p) complexes onto a streakcameraphotocathode fortime re...
Source: Review of Scientific Instruments - September 28, 2016 Category: Physics Authors: K. W. Hill, M. Bitter, L. Delgado-Aparicio, P. C. Efthimion, R. Ellis, L. Gao, J. Maddox, N. A. Pablant, M. B. Schneider, H. Chen, S. Ayers, R. L. Kauffman, A. G. MacPhee, P. Beiersdorfer, R. Bettencourt, T. Ma, R. C. Nora, H. A. Scott, D. B. Thorn, J. D. Source Type: research
Compact ECEI system with in-vessel reflective optics for WEST
An electron cyclotron emissionimaging (ECEI)diagnosticsystem for WEST (W Environment for Steady stateTokamak) is under development to study theMHD instabilities affected bytungsten impurities. Thesystem will provide 2-D Te fluctuationimages (width × height = ∼18 cm × ∼ 34 cm at low field side and ∼13 cm × ∼ 39 cm at high field side) from a poloidal cross section with highspatial ( ≤1.7 cm) and temporal (≤2 μs) resolutions. While the key concept and electronic structure are similar to that of prior ECEIsystems on othertokamak devices such as KSTAR, DIII-D, or ASDEX-U, part of theimaging optics ...
Source: Review of Scientific Instruments - September 28, 2016 Category: Physics Authors: Y. B. Nam, H. K. Park, W. Lee, G. S. Yun, M. Kim, R. Sabot, D. Elbeze, P. Lotte and J. Shen Source Type: research
Note: Electro-optic coefficients of Li-deficient MgO-doped LiNbO3 crystal
A number of Li-deficient MgO-doped LiNbO3 (LN) crystals with different Li2O contents ranging from 43.4 mol. % to 44.5 mol. % were prepared by carrying out the Li-poor vapor transport equilibration treatment on 5 mol. % (in growth melt) MgO-doped LN crystals. Unclampedelectro-optic (EO) coefficients γ13 and γ33 of these crystals were measured by Mach-Zehnder interferometry. The results show that γ13 ( γ33) increases linearly by ∼14% (11%) as the Li2O content decreases from 44.5 mol. % of the as-grown state to 43.4 mol. % of the Li-deficient state. This feature is desired for the EO application of the Li-deficient MgO:...
Source: Review of Scientific Instruments - September 28, 2016 Category: Physics Authors: Wan-Ying Du, Zi-Bo Zhang, Shuai Ren, Wing-Han Wong, Dao-Yin Yu, Edwin Yue-Bun Pun and De-Long Zhang Source Type: research
Ultrasonic micro-motor with multilayer piezoelectric ceramic and chamfered driving tips
In this study, an oblate-typeultrasonic micro-motor withmultilayerpiezoelectricceramic and chamfered driving tips was proposed and experimentally researched. The micro-motor works based on the standing-wave principle and has a higher rotary speed than the traditional standing-wave one in principle, reaching a rotary speed of 2100 r/min in this study at the voltage of 20 Vp −p. When the micro-motor rotates, single phase alternating current is required, namely,V=Asinωt, and exchanging the signal wire and ground wire will not change the rotary direction of the motor, which reinforces the safety and the compaction of this m...
Source: Review of Scientific Instruments - September 28, 2016 Category: Physics Authors: Yanqiang Zhao, Songmei Yuan, Xiangcheng Chu, Shuning Gao, Zuojin Zhong and Cong Zhu Source Type: research
Measurement of contact angles in a simulated microgravity environment generated by a large gradient magnetic field
In this study, we report the development and construction of a new setup that was specifically designed for use in a strongmagnetic field tomeasure the contact angle between a levitateddroplet and asolid surface. The application of the setup in a large gradientmagnetic field was tested, and the contact angles were readilymeasured. (Source: Review of Scientific Instruments)
Source: Review of Scientific Instruments - September 28, 2016 Category: Physics Authors: Yong-Ming Liu, Rui-Qing Chen, Zi-Qing Wu, Jing Zhu, Jian-Yu Shi, Hui-Meng Lu, Peng Shang and Da-Chuan Yin Source Type: research
Magnetic tweezers force calibration for molecules that exhibit conformational switching
High spatial and temporal resolution magnetic tweezers experiments allow for the directcalibration of pulling forces applied to short biomolecules. In one class of experiments, a force is applied to a structured RNA or protein to induce an unfolding transition; when the force is maintained at particular values, the molecule can exhibitconformational switching between the folded and unfolded states or between intermediate states. Here, we analyze the degree to which common forcecalibration approaches, involving the fitting ofmodel functions to the Allan variance or power spectral density of the bead trajectory, are biased b...
Source: Review of Scientific Instruments - September 28, 2016 Category: Physics Authors: David R. Jacobson and Omar A. Saleh Source Type: research
A kind of fast shutter for Z pinch diagnosis device
A kind of fast shutter for protecting the diagnosis devices inZ pinch experiments is introduced in this paper. The shutter is composed of a pulling rod, a magnetic core, and a solenoid. Different from the traditionalcoils which were used at the voltage of 220 V, the solenoid we used must endure the high voltage of 5 –10 kV and the deformation which maybe caused by the 5–10 T intense magnetic field. A creative configuration for the solenoid is developed including the winding guide, insulating sleeve, and stainless-steel sleeve. The experimental results show that the configuration of the solenoid is effective . The veloc...
Source: Review of Scientific Instruments - September 28, 2016 Category: Physics Authors: Liangping Wang, Xinjun Zhang, Tieping Sun and Wentin Mao Source Type: research
High-power ultrafast Yb:fiber laser frequency combs using commercially available components and basic fiber tools
We describe practical methods for achieving and characterizing low-noise single-pulse operation and long-term stability from Yb:fiberoscillators based on nonlinear polarization evolution. Stabilization of the combs using a variety of transducers, including a new method for tuning the carrier-envelope offset frequency, is discussed. High average power is achieved through chirped-pulse amplification in simple fiberamplifiers based on double-cladphotonic crystal fibers. We describe the use of these combs in several applications, including ultrasensitivefemtosecond time-resolved spectroscopy and cavity-enhanced high-order harm...
Source: Review of Scientific Instruments - September 27, 2016 Category: Physics Authors: Xinlong Li, Melanie A. R. Reber, Christopher Corder, Yuning Chen, Peng Zhao and Thomas K. Allison Source Type: research
A novel instrument to measure differential ablation of meteorite samples and proxies: The Meteoric Ablation Simulator (MASI)
On entering the Earth ’s atmosphere, micrometeoroids partially or completely ablate, leaving behind layers of metallic atoms and ions. The relative concentration of the various metal layers is not well explained by current models of ablation. Furthermore, estimates of the total flux of cosmic dust and meteoroids enteri ng the Earth’s atmosphere vary over two orders of magnitude. To better constrain these estimates and to better model the metal layers in the mesosphere, an experimental Meteoric Ablation Simulator (MASI) has been developed. Interplanetary Dust Particle (IDP) analogs are subjected totemperature profiles s...
Source: Review of Scientific Instruments - September 27, 2016 Category: Physics Authors: D. L. Bones, J. C. G ómez Martín, C. J. Empson, J. D. Carrillo Sánchez, A. D. James, T. P. Conroy and J. M. C. Plane Source Type: research
Note: A dual-chip stroboscopic pulsed RADAR for probing passive sensors
Stroboscopy provides an energy and computationally efficient means of sampling radiofrequency and microwave signals assumed to be reproducible under external excitation. While well known for impulse modeRADAR receivers, we here investigate its use for interrogatingsurface acoustic wave(SAW)transducers acting as passive cooperative targets. Amongst the originality of the implementation is the need to keep phase coherence between successive pulsegenerations which last up to tens of the radiofrequency periods to optimally transfer energy to thetransducer. A two-chip receiver architecture is demonstrated, with a trigger signal...
Source: Review of Scientific Instruments - September 27, 2016 Category: Physics Authors: F. Minary, D. Rabus, G. Martin and J.-M Friedt Source Type: research
Note: A manifold ranking based saliency detection method for camera
Research focused on salient object region in natural scenes has attracted a lot in computer vision and has widely been used in many applications like object detection and segmentation. However, an accurate focusing on the salient region, while taking photographs of the real-world scenery, is still a challenging task. In order to deal with the problem, this paper presents a novel approach based on humanvisual system, which works better with the usage of both background prior and compactness prior. In the proposed method, we eliminate the unsuitable boundary with a fixed threshold to optimize the image boundary selection whi...
Source: Review of Scientific Instruments - September 27, 2016 Category: Physics Authors: Libo Zhang, Yihan Sun, Tiejian Luo and Mohammad Muntasir Rahman Source Type: research
Imaging and image restoration of lens-combined modulated wavefront coding
In this paper, it presents a new wavefront coding (WFC) technology that we call lens-combined modulated wavefront coding (LM-WFC). Based on the LM-WFC design method, we establish a large depth of field and largeaperture system. Simulation results indicate that themodulation transfer function of the system has a defocus invariant characteristic, which all typical WFC systems have, with a large depth of field. Experimental results for comparing the LM-WFCimaging system and a traditionalimaging system are presented. The comparative results demonstrate that the LM-WFC system has animaging performance invariant over a wide dept...
Source: Review of Scientific Instruments - September 27, 2016 Category: Physics Authors: Yijian Wu, Liquan Dong, Yuejin Zhao, Ming Liu, Xuhong Chu, Wei Jia and Xiaohu Guo Source Type: research
A new system for continuous and remote monitoring of patients receiving home mechanical ventilation
Home mechanical ventilation is the treatment of patients with respiratory failure or insufficiency by means of a mechanical ventilator at a patient ’s home. In order to allow remote patient monitoring, several tele-monitoring systems have been introduced in the last few years. However, most of them usually do not allow real-time services, as they have their own proprietary communication protocol implemented and some ventilation parameters are not alwaysmeasured. Moreover, they monitor only some breaths during the whole day, despite the fact that a patient ’s respiratory state may change continuously during the day. In ...
Source: Review of Scientific Instruments - September 27, 2016 Category: Physics Authors: L. Battista Source Type: research
A virtual instrument to standardise the calibration of atomic force microscope cantilevers
Atomic force microscope(AFM) users often calibrate the spring constants of cantilevers using functionality built into individual instruments. Thiscalibration is performed without reference to a global standard, hindering the robust comparison offorce measurements reported by different laboratories. Here, we describe a virtual instrument (an internet-based initiative) whereby users from all laboratories can instantly and quantitatively compare theircalibrationmeasurements to those of others —standardisingAFM forcemeasurements —and simultaneously enabling non-invasivecalibration ofAFM cantilevers of any geometry. This gl...
Source: Review of Scientific Instruments - September 27, 2016 Category: Physics Authors: John E. Sader, Riccardo Borgani, Christopher T. Gibson, David B. Haviland, Michael J. Higgins, Jason I. Kilpatrick, Jianing Lu, Paul Mulvaney, Cameron J. Shearer, Ashley D. Slattery, Per-Anders Thor én, Jim Tran, Heyou Zhang, Hongrui Zhang and Tian Zheng Source Type: research
Integrated four-channel all-fiber up-conversion single-photon-detector with adjustable efficiency and dark count
Up-conversion single photondetector (UCSPD) has been widely used in many research fields includingquantum key distribution, lidar, optical time domain reflectrometry, and deep space communication. For the first time in laboratory, we have developed an integrated four-channel all-fiber UCSPD which can work in both free-running and gate modes. This compact module can satisfy different experimental demands with adjustabledetection efficiency and dark count. We have characterized the key parameters of the UCSPDsystem. (Source: Review of Scientific Instruments)
Source: Review of Scientific Instruments - September 27, 2016 Category: Physics Authors: Ming-Yang Zheng, Guo-Liang Shentu, Fei Ma, Fei Zhou, Hai-Ting Zhang, Yun-Qi Dai, Xiuping Xie, Qiang Zhang and Jian-Wei Pan Source Type: research
