A low-temperature external cavity diode laser for broad wavelength tuning
We report on the design and characterization of a low-temperature externalcavitydiode laser (ECDL) system for broad wavelength tuning. The performance achieved with multiplediode models addresses the scarcity of commercial redlaser diodes below 633 nm, which is a wavelength range relevant to the spectroscopy of many molecules and ions. Using a combination of multiple-stage thermoelectric cooling andwater cooling, the operatingtemperature of alaser diode is lowered to −64 °C, more than 85 °C below the ambienttemperature. The laser system integratestemperature anddiffraction grating feedback tunability for coarse and...
Source: Review of Scientific Instruments - November 10, 2016 Category: Physics Authors: William G. Tobias, Jason S. Rosenberg, Nicholas R. Hutzler and Kang-Kuen Ni Source Type: research
Versatile wetting measurement of microplate wells
A method to measure the contact angle, which is indicative ofwetting, using small liquid volumes dispensed directly on microplate wells is described and demonstrated. Experiments with enhanced greenprotein samples of volumes 4.4 –6μl showed no measured variance in the contact angle. Experiments with phosphate buffersolution with varied concentrations of a non-ionic detergent (Tween 20) dissolved, however, revealed smaller contact angles with increased detergent concentration. It is experimentally shown thatdrops can be located up to 7 ° from the lowest position of the well without affecting the accuracy of contact angl...
Source: Review of Scientific Instruments - November 9, 2016 Category: Physics Authors: Enoch Ming Wei Ng, Brandon Huey-Ping Cheong, Yang Yu, Oi Wah Liew and Tuck Wah Ng Source Type: research
Effect on measurement accuracy of transillumination using sawtooth-shaped-function optical signal
There exist lots of difficulties in opticaltransillumination of biologicaltissues, especially, low-level-light detection and low gray-scale resolution could reduce recognition accuracy of differences intissue. Aiming at the problems, this paper proposes a method for opticaltransillumination using sawtooth-shaped-function optical signal and frame accumulation technology to explore the spatial information of heterogeneity in thetissue. Sawtooth-shaped-function optical signal combined with frame accumulation technology is applied to realize the low-level-lightimage detection, where frame accumulation technology improves the s...
Source: Review of Scientific Instruments - November 9, 2016 Category: Physics Authors: Xue Yang, Yajia Hu, Gang Li and Ling Lin Source Type: research
New numerical simulation method to calibrate the regular hexagonal NaI(Tl) detector with radioactive point sources situated non-axial
Scintillation crystals are usually used fordetection of energeticphotons at room temperature in high energy and nuclear physics research, non-destructive analysis of materials testing, safeguards, nuclear treaty verification, geological exploration, and medical imaging. Therefore, new designs and construction of radioactive beam facilities are coming on-line with these science brunches. A good number of researchers are investigating the efficiency of the γ-raydetectors to improve the models and techniques used in order to deal with the most pressing problems in physics research today. In the present work, a new integrativ...
Source: Review of Scientific Instruments - November 9, 2016 Category: Physics Authors: Ayman Hamzawy, Dimitar N. Grozdanov, Mohamed S. Badawi, Fuad A. Aliyev, Abouzeid A. Thabet, Mahmoud I. Abbas, Ivan N. Ruskov, Ahmed M. El-Khatib, Yuri N. Kopatch and Mona M. Gouda Source Type: research
A novel microgripper hybrid driven by a piezoelectric stack actuator and piezoelectric cantilever actuators
In this study, a novel microgripper hybrid driven by a PSA and two PCAs is proposed, which can be a better solution for the issue, compared with the previous microgripper using PSA-driven multi-stages displacement amplification mechanism(DAM) or using longer and narrower PCAs. A compact one-stage orthogonalDAM is proposed for the PSA in the microgripper, which can enlarge the grasping stroke and realize parallel grasping movement. The proposed orthogonalDAM is a triangulation amplification-based mechanism with undetermined structural parameters. Bidirectional symmetric input forces/displacements are not required in the pro...
Source: Review of Scientific Instruments - November 9, 2016 Category: Physics Authors: Weilin Chen, Xianmin Zhang and Sergej Fatikow Source Type: research
Self-calibration method of the bias of a space electrostatic accelerometer
The high precision spaceelectrostatic accelerometer is an instrument tomeasure the non-gravitational forces acting on aspacecraft. It is one of the key payloads for satellite gravitymeasurements and space fundamental physics experiments. Themeasurement error of the accelerometer directly affects the precision of gravity field recovery for the earth. This paperanalyzes the sources of the bias according to the operating principle and structural constitution of the spaceelectrostatic accelerometer.Models of bias due to the asymmetry of the displacement sensing system, including the mechanical sensor head and thecapacitance se...
Source: Review of Scientific Instruments - November 9, 2016 Category: Physics Authors: Shao-Bo Qu, Xiao-Mei Xia, Yan-Zheng Bai, Shu-Chao Wu and Ze-Bing Zhou Source Type: research
A total station spatial positioning method based on rotary laser scanning and ultrasonic ranging
Total stationspatial coordinator measuring technology is extensively applied in the large-scale measurement of industrial assembly and manufacturing for its flexibility and adaptability. The existing total station technology has some principal limits such as poor efficiency and single tasking; in order to achieve the total stationspatial coordinator measuring technology with the advantages of multi-task, real-time measurement, and high accuracy, this paper presents a novel total station measurement method by using multi-laser plane constraints established through rotating planar planes and distance information obtained wit...
Source: Review of Scientific Instruments - November 8, 2016 Category: Physics Authors: Jun Wu, Jigui Zhu, Zhijing Yu, Jingchang Zhuge and Bin Xue Source Type: research
A compact and versatile dynamic flow cryostat for photon science
We have developed a helium gas flow cryostat for use on synchrotron tender to hardX-ray beamlines. Very efficient sample cooling is achieved because the sample is placed directly in the cooling helium flow on a removablesample holder. The cryostat is compact and easy to operate; samples can be changed in less than 5 min at any temperature. The cryostat has a temperature range of 2.5 –325 K with temperature stability better than 0.1 K. The very wide optical angle and the ability to operate in any orientation mean that the cryostat can easily be adapted for differentX-ray techniques. It is already in use on different beaml...
Source: Review of Scientific Instruments - November 8, 2016 Category: Physics Authors: Peter J. E. M. van der Linden, Marco Moretti Sala, Christian Henriquet, Matteo Rossi, Kenya Ohgushi, Fran çois Fauth, Laura Simonelli, Carlo Marini, Edmundo Fraga, Claire Murray, Jonathan Potter and Michael Krisch Source Type: research
A compact five-port waveguide structure and its application as a three-way power divider
A compact five-port waveguide structure consisting of three rectangular ports, one coaxial port, and one circular waveguide port is proposed. The three rectangular waveguides are uniformly distributed in space at angles of 120 °, and the coaxial and circular waveguides are located at the top and bottom, respectively, of the rectangular waveguides. The ideal scattering matrix is derived from the symmetry properties of the structure. If the circular and coaxial ports are matched, then the entire five-port waveguide structu re is automatically matched. Two connected inserted coaxial probes, a frustum, and a coaxial transitio...
Source: Review of Scientific Instruments - November 8, 2016 Category: Physics Authors: Letian Guo, Jiawei Li, Tao Ba, Wenhua Huang and Hao Shao Source Type: research
Ultra-high vacuum compatible preparation chain for intermetallic compounds
We report the development of a versatile material preparation chain forintermetallic compounds, which focuses on the realization of a high-puritygrowth environment. The preparation chain comprises an argon glovebox, an inductively heated horizontal coldboatfurnace, an arc meltingfurnace, an inductively heated rod castingfurnace, an optically heated floating-zonefurnace, a resistively heated annealingfurnace, and an inductively heated annealingfurnace. The coldboatfurnace and the arc meltingfurnace may be loaded from the glovebox by means of a load-lock permitting to synthesize compounds starting with air-sensitive elements...
Source: Review of Scientific Instruments - November 8, 2016 Category: Physics Authors: A. Bauer, G. Benka, A. Regnat, C. Franz and C. Pfleiderer Source Type: research
Calibrating ion density profile measurements in ion thruster beam plasma
Theion thrusterbeamplasma is characterized by high directed ionvelocity (104 m/s) and lowplasma density (1015 m−3). Interpretation ofmeasurements of such aplasma based on classicalLangmuir probe theory can yield a large experimental error. This paper presents an indirect method to calibrate ion density determination in anion thrusterbeamplasma using a Faraday probe, a retarding potential analyzer, and aLangmuir probe. This new method is applied to determine theplasma emitted from a 20-cm-diameter Kaufmanion thruster. The results show that the ion density calibrated by the new method can be as much as 40% less than that w...
Source: Review of Scientific Instruments - November 8, 2016 Category: Physics Authors: Zun Zhang, Haibin Tang, Junxue Ren, Zhe Zhang and Joseph Wang Source Type: research
Analysis of magnetically immersed electron guns with non-adiabatic fields
Electron diode guns, which have strongly varying magnetic orelectric fields in a cathode-anode gap, were investigated in order to generate laminarelectron beams with highcurrent density using magnetically immersed guns. By creating a strongly varying radialelectric field in a cathode-anode gap of the electron gun, it was demonstrated that the optical properties of the gun can be significantly altered, which allows the generation of a laminar, high-currentelectron beam with relatively lowmagnetic field on thecathode. The relatively high magnetic compression of theelectron beam achieved by this method is important for produc...
Source: Review of Scientific Instruments - November 8, 2016 Category: Physics Authors: Alexander Pikin, James G. Alessi, Edward N. Beebe, Deepak Raparia and John Ritter Source Type: research
Cryogenic setup for trapped ion quantum computing
We report on the design of a cryogenic setup for trapped ion quantum computing containing a segmented surface electrode trap. The heat shield of our cryostat is designed to attenuate alternatingmagnetic field noise, resulting in 120 dB reduction of 50 Hz noise along themagnetic field axis. We combine this efficientmagnetic shielding with high optical access required for single ion addressing as well as for efficient state detection by placing two lenses each with numerical aperture 0.23 inside the inner heat shield. The cryostat design incorporates vibration isolation to avoid decoherence of opticalqubits due to the motion...
Source: Review of Scientific Instruments - November 8, 2016 Category: Physics Authors: M. F. Brandl, M. W. van Mourik, L. Postler, A. Nolf, K. Lakhmanskiy, R. R. Paiva, S. M öller, N. Daniilidis, H. Häffner, V. Kaushal, T. Ruster, C. Warschburger, H. Kaufmann, U. G. Poschinger, F. Schmidt-Kaler, P. Schindler, T. Monz and R. Blatt Source Type: research
A novel multi-channel quadrature Doppler backward scattering reflectometer on the HL-2A tokamak
A novel 16-channel fixed frequencyDoppler backward scattering (DBS)reflectometer system has been developed on the HL-2A tokamak. This system is based on the filter-based feedback loopmicrowave source (FFLMS) technique, which has lower phase noise and lower power variation compared with present tunable frequency generation and comb frequency array generation techniques [J. C. Hillesheimet al. Rev. Sci. Instrum.80, 083507 (2009) and W. A. Peebleset al. Rev. Sci. Instrum.81, 10D902 (2010)]. The 16-channel DBS system is comprised of four × four-frequencymicrowave transmitters and direct quadrature demodulation receivers. The ...
Source: Review of Scientific Instruments - November 7, 2016 Category: Physics Authors: Zhongbing Shi, Wulu Zhong, Min Jiang, Zengchen Yang, Boyu Zhang, Peiwan Shi, Wei Chen, Jie Wen, Chengyuan Chen, Bingzhong Fu, Zetian Liu, Xuantong Ding, Qingwei Yang and Xuru Duan Source Type: research
Orientation –free and differentially pumped addition of a low-flux reactive gas beam to a surface analysis system
We describe an example of a piecewise gaschamber that can be customized to incorporate a low flux of gas-phase radicals with an existing surface analysischamber forin situ and stepwise gas-surface interaction experiments without any constraint in orientation. The piecewise nature of this gaschamber provides complete angular freedom and easy alignment and does not require any modification of the existing surface analysischamber. In addition, the entire gas-surface system is readily differentially pumped with the surfacechamber kept under ultra-high-vacuum during the gas-surface measurements. This new design also allows not ...
Source: Review of Scientific Instruments - November 7, 2016 Category: Physics Authors: Colin Harthcock, Abdolreza Jahanbekam, Jeremy R. Eskelsen and David Y. Lee Source Type: research
