The sample is positioned using a stable mechanical design to minimize vibration and drift and employs precise translation stages to enable nanobeam experiments. Results of in situ x-ray characterization of the amorphous thin film deposition process for a SrTiO3/BaTiO3 multilayer illustrate implementation of this instrument.A pulsed power supply with a compact and low-cost electric-double-layer-capacitor (EDLC) is developed for generating pulsed magnetic fields with a long pulse duration of a few seconds. The system is demonstrated in three experimental setups using a 10.7 F- or 50 F-EDLC capacitor bank. By using the 10.7 F-EDLC capacitor bank with a 27 mm wide-bore magnet, the pulsed magnetic field with a peak field strength of 24.3 T and a pulse duration of ∼1 s is generated. The field profiles are reproduced in the theoretical calculations taking Joule heating into account. The calculations are also used to discuss possible variations of the field profile for future investigations.For beam profile measurement of high-intensity proton beams in the low-energy high-intensity proton accelerator at Bhabha Atomic Research Centre, a recent noninvasive technique based on gas sheets will be explored. The gas sheet for this instrument needs to be characterized for calibration and fine tuning of the sheet properties to provide better profile measurements. Pulsed sheet generators for similar applications have been characterized using movable vacuum chambers with a small slit and a gauge mounted inside. https://www.selleckchem.com/products/jnj-75276617.html Pitot probes are more compact instruments and have been used to measure gas jet profiles in molecular beam applications where the jet was not pulsed. The performance of Pitot probes in the measurement of pulsed supersonic gas flow in vacuum was, therefore, investigated in this work. A test system was developed to generate a pulsed supersonic gas jet in vacuum, and a Pitot probe was inserted into the flow at various axial locations with respect to the nozzle. Measurements taken along the nozzle axis using this probe, as well as the axial Mach number and impact pressure computed using computational fluid dynamics and direct simulation Monte Carlo algorithms, were compared with fitting formulas. Schlieren images of the jet with and without the Pitot tube were also taken under different vacuum conditions.A dual trace intra-pulse and inter-pulse spatio-spectral interferometer has been set up to study the temporal stability of a ∼200 fs duration laser pulse train from a cw mode-locked laser oscillator. Simultaneous recording of twin interferograms helps identify the phase error in inter-pulse interferograms due to the diagnostic setup kept in a standard laboratory environment. Applicability of inter-pulse tilted pulse-front interferograms has been demonstrated to constitute an alternative inexpensive method for visual detection and estimation of phase slippage and pulse repetition frequency of an ultra short pulse train. The effect of pump beam intensity on the repetition rate of pulses due to accumulated intra-cavity non-linear phase shifts is also presented.We show that a cryogenic amplifier composed of a homemade GaAs high-electron-mobility transistor (HEMT) is suitable for current-noise measurements in a mesoscopic device at dilution-refrigerator temperatures. The lower noise characteristics of our homemade HEMT lead to a lower noise floor in the experimental setup and enable more efficient current-noise measurement than is available with a commercial HEMT. We present the dc transport properties of the HEMT and the gain and noise characteristics of the amplifier. With the amplifier employed for current-noise measurements in a quantum point contact, we demonstrate the high resolution of the measurement setup by comparing it with that of the conventional one using a commercial HEMT.In this paper, we present a cable-driven exoskeleton with variable stiffness for upper limb rehabilitation. Adjustable stiffness of the cable-driven exoskeleton is achieved by attaching a novel variable stiffness module (VSM) to each driving cable. The module is able to vary stiffness in a large range through changing cable tension. In this paper, a stiffness model is developed for a cable-driven exoskeleton to reveal the stiffness performance of the exoskeleton with the influence of VSMs. Based on the stiffness model, a controller with stiffness-oriented strategy is proposed to vary the stiffness of the exoskeleton. Experiments on a prototype of a cable-driven exoskeleton are conducted to validate the controller.Fiber-optic bolometers (FOBs) intended for plasma radiation measurement in magnetically confined fusion have been previously developed using a silicon pillar that functions as both a Fabry-Perot interferometer (FPI) for temperature measurement and an absorber for the radiation. We report an FOB design that can significantly improve the detection sensitivity over earlier designs by engineering the absorber of the FOB. Our design uses the fact that, compared with a silicon pillar, a gold film with the same x-ray absorption thickness will show a much higher temperature rise from a given power density of the radiation. Therefore, the responsivity of an FOB can be improved by attaching a large gold disk to the silicon FPI as the absorber. We have developed a fabrication method for FOBs of such design and obtained an FOB with a 4-µm-thick, 0.6-mm-diameter gold disk attached to a 200-µm-diameter, 100-µm-thick silicon FPI. We have characterized the noise, responsivity, response time, and noise-equivalent power density (NEPD) and compared these with the earlier design where the absorber is mainly the silicon FPI itself. The experimental result suggests that the FOB with the gold disk achieves a responsivity of ∼2.8 mK/(W/m2) and a noise-equivalent-power-density of 0.13 W/m2, which are, respectively, more than nine times larger and six times smaller compared to the FOB using a previous design. Improved NEPD and good absorption over a broad frequency range will make the FOB more attractive for applications in magnetic-confinement fusion devices.The electron cyclotron resonance heating system is one of the most effective plasma heating systems for controlled nuclear fusion. The key part of the system called gyrotron is driven by a high voltage power supply with a rated output power of hundreds of kilowatts. When the system is in operation, breakdowns frequently occur in the gyrotron. During breakdowns, the gyrotron will endure a large volume of energy and may be damaged. A solid-state switch is required to protect it by blocking high voltage (∼40 kV) within 10 microseconds and limiting energy within a few joules. Compared with Si IGBT/MOSFET, SiC MOSFET with higher switching speed is more suitable for the switch. However, rapid switching speed exacerbates the voltage imbalance. To solve the problems, a reliable module named Advanced Chopper Sub-Model based on SiC MOSFETs for a solid-state switch is proposed. The module adopts a voltage-clamped circuit to achieve the capabilities of rapid switching-off speed, as well as low overvoltage and good voltage balancing.