Low power RF amplifier circuit for ion trap applications
A low power RFamplifier circuit forion trap applications is presented and described. Theamplifier is based on a class-D half-bridgeamplifier with a voltage mirror driver. The RFamplifier is composed of an RF class-Damplifier, an envelope modulator to ramp up the RF voltage during the ionanalysis stage, a detector or amplitude demodulation circuit for sensing the output signal amplitude, and a feedbackamplifier that linearizes the steady state output of theamplifier. The RF frequency is set by a crystaloscillator and the series resonant circuit is tuned to theoscillator frequency. The resonant circuit components have been c...
Source: Review of Scientific Instruments - September 20, 2016 Category: Physics Authors: J. R. Noriega, L. A. Garc ía-Delgado, R. Gómez-Fuentes and A. García-Juárez Source Type: research
Moving target detection for frequency agility radar by sparse reconstruction
Frequency agilityradar, with randomly varied carrier frequency from pulse to pulse, exhibits superior performance compared to the conventional fixed carrier frequency pulse-Dopplerradar against theelectromagnetic interference. A novel moving target detection (MTD) method is proposed for the estimation of the target ’s velocity of frequency agilityradar based on pulses within acoherent processing interval by using sparse reconstruction. Hardware implementation of orthogonal matching pursuit algorithm is executed on Xilinx Virtex-7 Field Programmable Gata Array (FPGA) to perform sparse optimization. Finally, a series of ex...
Source: Review of Scientific Instruments - September 20, 2016 Category: Physics Authors: Yinghui Quan, YaChao Li, Yaojun Wu, Lei Ran, Mengdao Xing and Mengqi Liu Source Type: research
Piezoelectric tunable microwave superconducting cavity
In the context of engineered quantum systems, there is a demand forsuperconducting tunabledevices, able to operate with high-quality factors at power levels equivalent to only a fewphotons. In this work, we developed a 3Dmicrowave re-entrantcavity with such characteristics ready to provide a very fine-tuning of a high-Qresonant mode over a large dynamic range. This system has an electronic tuning mechanism based on a mechanically amplifiedpiezoelectric actuator, which controls theresonator dominant mode frequency by changing thecavity narrow gap by very small displacements. Experiments were conducted at room and dilutionre...
Source: Review of Scientific Instruments - September 20, 2016 Category: Physics Authors: N. C. Carvalho, Y. Fan and M. E. Tobar Source Type: research
Plasmakristall-4: New complex (dusty) plasma laboratory on board the International Space Station
New complex-plasma facility, Plasmakristall-4 (PK-4), has been recently commissioned on board the International Space Station. Incomplex plasmas, the subsystem ofμm-sized microparticles immersed in low-pressure weakly ionized gas-dischargeplasmas becomes strongly coupled due to the high (103–104 e) electric charge on the microparticle surface. The microparticle subsystem ofcomplex plasmas is available for the observation at the kinetic level, which makescomplex plasmas appropriate for particle-resolved modeling of classical condensed matter phenomena. The main purpose of PK-4 is the investigation of flowingcomplex plasm...
Source: Review of Scientific Instruments - September 20, 2016 Category: Physics Authors: M. Y. Pustylnik, M. A. Fink, V. Nosenko, T. Antonova, T. Hagl, H. M. Thomas, A. V. Zobnin, A. M. Lipaev, A. D. Usachev, V. I. Molotkov, O. F. Petrov, V. E. Fortov, C. Rau, C. Deysenroth, S. Albrecht, M. Kretschmer, M. H. Thoma, G. E. Morfill, R. Seurig, A Source Type: research
Broadband UV-Vis vibrational coherence spectrometer based on a hollow fiber compressor
We describe abroadband transientabsorption (TA) spectrometer devised to excite and probe, in the blue to UV range, vibrationalcoherencedynamics in organic molecules in condensed phase. A 800-nm Ti:Sa amplifier and a hollow fiber compressor are used to generate a 6-fs short pulse at 1 kHz.Broadband sum frequency generation with the fundamental pulse is implemented to produce a 400-nm, 8-fs Fourier limited short pulse. A UV-Vis white-light supercontinuum is implemented as a probe with intensity self-referencing to achieve a shot-noise-limited sensitivity. Rapid scanning of the pump-probe delay is shown very efficient in supp...
Source: Review of Scientific Instruments - September 20, 2016 Category: Physics Authors: Moussa Gueye, Julien Nillon, Olivier Cr égut and Jérémie Léonard Source Type: research
Measurement and simulation of the response function of time of flight enhanced diagnostics neutron spectrometer for beam ion studies at EAST tokamak
The 2.5 MeV TOFED(Time-Of-Flight EnhancedDiagnostics)neutron spectrometer with a double-ring structure has been installed at Experimental Advanced Superconducting Tokamak (EAST) to perform advancedneutron emission spectroscopydiagnosis of deuterium plasmas. This work describes the response function of the TOFED spectrometer, which is evaluated for the fully assembled instrument in its final layout. Results from Monte Carlo simulations and dedicated experiments with pulsed light sources are presented and used to determine properties of lighttransport from the scintillator. A GEANT4 model of the TOFED spectrometer was develo...
Source: Review of Scientific Instruments - September 20, 2016 Category: Physics Authors: X. Y. Peng, Z. J. Chen, X. Zhang, T. F. Du, Z. M. Hu, L. J. Ge, Y. M. Zhang, J. Q. Sun, G. Gorini, M. Nocente, M. Tardocchi, L. Q. Hu, G. Q. Zhong, N. Pu, S. Y. Lin, B. N. Wan, X. Q. Li, G. H. Zhang, J. X. Chen and T. S. Fan Source Type: research
Preface: Proceedings of the 21st Topical Conference on High-Temperature Plasma Diagnostics, Madison, Wisconsin, USA 5-9 June 2016
(Source: Review of Scientific Instruments)
Source: Review of Scientific Instruments - September 20, 2016 Category: Physics Authors: George R. McKee Source Type: research
Pulse shaping techniques for a high-g shock tester based on collision principle
Pulse shaping techniques are discussed in this paper for the practicability of a developed high-g shock tester. The tester is based on collision principle where there is a one-level velocityamplifier. Atheoretical and experimental study ofpulse shaping techniques is presented. A model was built andtheoretical formulae were deduced for the shock peakacceleration and its duration. Thentheoreticalanalysis and some experiments were conducted. The test results verify the validity oftheoretical model and show that the shock tester can generate the expected high-g shock pulses by integrated usage of differentimpact velocities and...
Source: Review of Scientific Instruments - September 19, 2016 Category: Physics Authors: Zhengyong Duan, Chuansheng Tang, Yang Li, Junliang Han and Guoxiong Wu Source Type: research
An algorithm for circular test and improved optical configuration by two-dimensional (2D) laser heterodyne interferometer
Circular test is an important tactic to assess motion accuracy in many fields especiallymachine tool and coordinatemeasuring machine. There are setup errors due to using directly centring of themeasuring instrument for both of contact double ball bar and existed non-contact methods. To solve this problem, an algorithm for circular test using function construction based on matrix operation is proposed, which is not only used for the solution of radial deviation (F) but also should be applied to obtain two other evaluation parameters especially circular hysteresis (H). Furthermore, an improved optical configuration with a si...
Source: Review of Scientific Instruments - September 19, 2016 Category: Physics Authors: Shanzhi Tang, Shengrui Yu, Qingfu Han, Ming Li and Zhao Wang Source Type: research
Piezoelectric energy harvesting computer controlled test bench
In this paper a newcomputer controlled (C.C.) laboratory test bench is presented. The patented test bench is made up of a C.C. road traffic simulator, C.C. electronic hardware involved in automatingmeasurements, and test bench controlsoftware interface programmed in LabVIEW ™. Our research is focused on characterizing electronic energy harvesting piezoelectric-based elements in road traffic environments to extract (or “harvest”) maximum power. In mechanical to electrical energy conversion, mechanical impacts or vibrational behavior are commonly used, and several major problems need to be solved to perform optimal har...
Source: Review of Scientific Instruments - September 19, 2016 Category: Physics Authors: M. V ázquez-Rodriguez, F. J. Jiménez, J. de Frutos and D. Alonso Source Type: research
A microfabricated sun sensor using GaN-on-sapphire ultraviolet photodetector arrays
A miniaturesensor for detecting the orientation of incidentultraviolet light was microfabricated usinggallium nitride (GaN)-on-sapphire substrates and semi-transparent interdigitatedgoldelectrodes for sun sensing applications. The individual metal-semiconductor-metalphotodetector elements were shown to have a stable and repeatable response with a high sensitivity (photocurrent-to-dark current ratio (PDCR) = 2.4 at −1 V bias) and a high responsivity (3200 A/W at −1 V bias) underultraviolet (365 nm)illumination. The 3 × 3 GaN-on-sapphireultravioletphotodetector array was integrated with agold aperture to realize a minia...
Source: Review of Scientific Instruments - September 19, 2016 Category: Physics Authors: Ruth A. Miller, Hongyun So, Heather C. Chiamori, Ateeq J. Suria, Caitlin A. Chapin and Debbie G. Senesky Source Type: research
Research of optical rotation measurement system based on centroid algorithm
Anoptical rotationmeasurementsystem based on digital signal processor, modulated laser, and step motor rotating stage is established. Centroid algorithm featured fast and simple calculation is introduced to process light signals with or without sample to obtain the optical rotating angle through the step difference between two centroids. Thesystem performance is proved experimentally with standardquartz tubes and glucose solutions. After variousmeasurements, the relative error and precision of thesystem are determined to 0.4% and 0.004 °, which demonstrates the reliable repeatability and high accuracy of wholemeasurements...
Source: Review of Scientific Instruments - September 19, 2016 Category: Physics Authors: Junjie Cao, Hongzhi Jia, Xinrong Shen and Shixin Jiang Source Type: research
Comb mode filtering silver mirror cavity for spectroscopic distance measurement
In this work we present a design of an externaloptical cavity based onFabry-Perotetalons applied to a 100 MHz Er-doped fiber opticalfrequency comb working at 1560 nm to increase its repetition frequency. AFabry-Perotcavity is constructed based on a transportable cage system with twosilvermirrors in plano-concave geometry including the mode-matching lenses, fiber coupled collimation package and detection unit. The system enables full 3D anglemirror tilting and x-y off axis movement as well as distance between themirrors. We demonstrate the increase of repetition frequency by direct measurement of the beat frequency and spec...
Source: Review of Scientific Instruments - September 19, 2016 Category: Physics Authors: R. Šmíd, A. Hänsel, L. Pravdová, J. Sobota, O. Číp and N. Bhattacharya Source Type: research
Experimentally determining the relative efficiency of spherically bent germanium and quartz crystals
We have used the EBIT-Ielectron beam ion trap at the Lawrence Livermore National Laboratory and a duplicate Orion High ResolutionX-ray Spectrometer (OHREX) to measure the relative efficiency of a spherically bentquartz (101̄1) crystal (2d = 6.687 Å) and a spherically bentgermanium (111) crystal (2d = 6.532 Å). L-shellX-ray photons from highly chargedmolybdenum ions generated in EBIT-I were simultaneously focussed and Bragg reflected by each crystal, both housed in a singlespectrometer, onto a single CCDX-ray detector. The flux from each crystal was then directly compared. Our results show that thegermanium crystal has a...
Source: Review of Scientific Instruments - September 19, 2016 Category: Physics Authors: G. V. Brown, P. Beiersdorfer, N. Hell and E. Magee Source Type: research
A single-shot spatial chirp method for measuring initial AC conductivity evolution of femtosecond laser pulse excited warm dense matter
To study the rapid evolution of ACconductivity from ultrafast laser excited warm dense matter(WDM), aspatialchirp single-shot method is developed utilizing a crossing angle pump-probe configuration. The pump beam is shaped individually in twospatial dimensions so that it can provide both sufficient laser intensity to excite the material to warm dense matter state and a uniform time window of up to 1 ps with sub-100 fs FWHM temporal resolution. Temporal evolution of ACconductivity in laser excited warm densegold was alsomeasured. (Source: Review of Scientific Instruments)
Source: Review of Scientific Instruments - September 19, 2016 Category: Physics Authors: Z. Chen, P. Hering, S. B. Brown, C. Curry, Y. Y. Tsui and S. H. Glenzer Source Type: research
