Review of Scientific Instruments最新文献

A scalable control architecture for superconducting quantum processors is essential as the number of qubits increases and coherent multi-qubit operations span beyond the capacity of a single control module. The Quantum Instrumentation Control Kit (QICK), built on AMD RFSoC platforms, offers a flexible open-source framework for pulse-level qubit control but lacks native support for multi-board synchronization, limiting its applicability to mid- and large-scale quantum devices. To overcome this limitation, we introduce Manarat, a scalable multi-board control platform based on QICK that incorporates hardware, firmware, and software enhancements to enable sub-100 ps timing alignment across multiple AMD ZCU216 RFSoC boards. Our system integrates a low-jitter clock distribution network, modifications to the tProcessor, and a synchronization scheme to ensure deterministic alignment of program execution across boards. It also includes a custom analog front-end for flux control that combines high-speed RF signals with software-programmable DC biasing voltages generated by a low-noise, high-precision DAC. These capabilities are complemented by a software stack capable of orchestrating synchronized multi-board experiments and fully integrated with the open-source Qibo framework for quantum device calibration and algorithm execution. We validate Manarat on a 10-qubit superconducting processor controlled by two RFSoC boards, demonstrating reliable execution of synchronized control sequences for cross-board CZ gate calibration. These results confirm that sub-nanosecond synchronization and coherent control are achievable across multiple RFSoC boards, enabling scalable operation of superconducting quantum computers.

Thermal deformation of x-ray optical elements, especially the first element exposed to high thermal loads, can significantly degrade the performance of synchrotron radiation beamlines. Accurate wavefront measurement is essential for estimating such deformations and improving optical design. Talbot interferometry, employing phase and absorption gratings to produce moiré fringes, enables wide-field wavefront sensing across areas of several to tens of millimeters. However, mismatches in the designed period ratio between the gratings introduce systematic errors in wavefront curvature estimation and surface profile reconstruction. This study investigates the impact of such period mismatches on wavefront accuracy and presents a practical calibration method. Experiments with both minimally used and long-term exposed gratings show that calibration markedly improves the precision of surface profile measurements, reducing variation by up to 50%. These results emphasize the importance of precise grating period calibration for reliable wavefront and surface figure evaluation, particularly for optics subject to thermal deformation under high-power x-ray irradiation.

A new L-shaped molecular beam Fourier transform microwave spectrometer (L-FTMW) has been developed at Tennessee Tech University to perform both cavity and chirped-pulse rotational spectroscopy within a single platform. The instrument features an L-shaped high-vacuum chamber comprised of stainless-steel and polycarbonate sections, allowing orthogonal operation of Fabry-Perot cavity and chirped-pulse configurations without mechanical reconfiguration. This paper focuses on the design, operation, and performance of the 8-18 GHz Fabry-Perot cavity subsystem within the L-FTMW spectrometer. The cavity is formed by two 7.5-inch-diameter aluminum mirrors with 30 cm radii of curvature, arranged near-confocally and coupled to a near-coaxial pulsed molecular beam. A custom Python-based interface enables automated high-resolution mapping of cavity resonances and broadband data acquisition with minimal user intervention. The system routinely achieves 2 kHz frequency resolution, enabling precise measurement of hyperfine spectral features. Performance was validated through measurements of benchmark systems, including OCS isotopologues and their weakly bound van der Waals complexes. The 17O13CS isotopologue (natural abundance = 0.000 397 2%, corresponding to ∼40 ppb in a 1% OCS/argon mixture) was detected within 5 min of signal averaging at natural abundance with argon as the carrier gas. The simple mechanical design and open-source control software make the L-FTMW spectrometer a versatile and accessible platform for high-resolution rotational spectroscopy and future investigations of reaction dynamics and kinetics.

Adjustable magnetic field sources have become indispensable in advanced material characterization techniques. Among these, permanent magnet assemblies offer significant advantages by reducing power consumption and minimizing Joule heating. In this work, we report on the development and integration of a tunable magnetic sample environment at the SoftiMAX beamline of the MAX IV synchrotron, employing a "magnetic mangles" configuration of four diametrically magnetized cylindrical NdFeB permanent magnets. This arrangement provides precise control of the field strength and orientation, achieving magnitudes up to 415 mT. Both in-plane and out-of-plane magnetic field configurations were explored, including a 30° tilted orientation. Our results indicate that the highest field uniformity occurs at maximum field strengths, decreasing as the field strength approaches zero. Moreover, field sweeping configurations were explored for various field orientation angles, and the hysteretic behavior as well as the field uniformity were analyzed. The system's performance was demonstrated through x-ray microscopy experiments conducted on Co nanochains and a CoGd thin film, revealing details of magnetic domain structures and magnetization reversal processes.

Semiconductor materials characterized by wide-bandgaps are well-suitable for measuring and detecting high-energy particles, such as x rays. According to the insulating properties of metal oxides and the sensing capabilities of two-dimensional nanomaterials, magnesium oxide (MgO) becomes a promising sensing material. To change the sensing behavior of composites, metal nanoparticles used to capitalize on their synergistic effects and change in reactions. According to this, magnesium oxide/gold (MgO/Au) nanocomposite was synthesized using facile and straightforward methods, namely laser ablation in liquid and magnetic stirring. In the study of electric response to x ray, it was observed that, compared to the energy change in photons, the MgO/Au nanocomposite shows higher sensitivity to intensity changes in x radiation. In contrast, MgO nanosheets demonstrate sensitivity to energy and intensity changes in radiation. With precise ammeter and appropriate analysis, these materials, when placed in the same device, have the potential to measure the energy and intensity of x rays. It is well established that semiconductors such as MgO with wide-energy-bandgaps exceeding 5 eV can demonstrate resistances in the megaohm range in prepared samples for analysis. Due to this elevated resistance, the electric current flowing through the biased material typically falls within the hundreds of picoamperes (pA). Such low current levels pose significant challenges for measurement using standard and even advanced ammeters, as they are highly susceptible to interference from noise sources. To mitigate this challenge, we have developed and evaluated a circuit designed to supply the necessary bias voltage and accurately measure extremely low electrical currents, specifically at the 10 pA level.

Reducing sample volumes for electron paramagnetic resonance (EPR) spectroscopy applications places increasing demands on hardware design to preserve or enhance EPR signal intensity. This work presents the design, fabrication, and testing of dielectric resonators and multi-channel aqueous sample cells for applications in X-band (nominally 9.5 GHz) EPR. Our aim was to maximize the EPR signal intensity for sample sizes of 3-4 μl and 200 nl. These advances are summarized as follows: single-crystal sapphire and rutile dielectric resonators with very low loss tangent and high resonator efficiency; minimum dielectric resonator coupling to radiation shield to reduce ohmic losses; 3D-printed aqueous sample cells with thin multi-channel construction to minimize radio frequency dissipation in the sample; and a Gordon coupler for maximum coupling range and minimum stored energy to eliminate frequency shifts during tuning. Sample tube cross sections were designed by leveraging insights gained from analytic theory to inform finite-element modeling of electromagnetic fields. Experimental comparisons of multi-channel sample cells using a sapphire resonator exhibited a 2.2-fold increase in EPR signal intensity compared with a standard capillary at 3-4 μl, while simulations predict an additional 23% improvement with further 3D printing advances. For samples at 200 nl, a rutile dielectric resonator with a multi-channel sample cell was simulated to improve EPR sensitivity by a 2.7-fold increase compared with a capillary at the same volume.

This paper presents a systematical transmission coil design method for a dual-load wireless power transfer (WPT) system based on a rectangular coil structure. The main design steps are as follows: (1) The system circuit model and the mathematical dimension model of the coupling coils are established to determine the inductance range of the receiving coil and the transmitting coil. (2) Three coil inductance calculation methods such as the finite element method (FEM), greenhouse formula method and backpropagation neural network (BPNN) are analyzed and compared. The FEM and BPNN hybrid method are finally selected for determining the relationship between rectangular coil size, coil turns, and inductance, which is a more efficient modeling scheme and can achieve enough modeling accuracy. (3) Based on calculated inductance characteristics, the length and width of the rectangular coil can be obtained with a geometric mapping scheme, and moreover, the coil size with optimal costs can be estimated. Detailed theoretical analyses are provided. Finally, simulations and experiments are performed for verification.

Despite the technological advancement in blood-contacting biomedical devices, issues related to thrombosis remain a persistent challenge. These devices not only include implants such as artificial heart valves and stents but also surgical tools and instruments. This makes hemocompatibility an important parameter to be considered before developing any material for a blood-contacting device. The two oldest methods, including the mechanical tilting method and the free-hemoglobin method, lack temporal accuracy and quantitative analysis. Our work gives an accurate and quantitative analysis to measure the blood clotting time of various materials that can be used as implant devices. The system relies on measuring the change of reflectance as blood clots on a surface and measures the clotting time and rate by analyzing the time dependent reflectance curve. The system consists of an automated injection system, a heater and temperature controller, a red laser and polarizer assembly, and a highly sensitive photodetector. As the blood clotting process begins, the sample surface becomes turbid, causing a change in voltage in the detector. The time taken for this "voltage change" corresponds to clotting time. Our system shows a prothrombin time of 12.6 s and an activated partial thromboplastin time of 31.16 s on the PTFE surface, close to the control due to its hydrophobicity. The electronics and device configuration used in our system give a temporal resolution of 5.7 ± 0.6 ms in the clotting time determination. Our design is compact, precise, accurate, and devoid of manual observation and errors.

The focus of this paper is on the development of an apparatus capable of rapid and precise temperature control of liquid samples circulated through a small-bore glass capillary over a range from -20 to 130 °C, with stability better than 10 mK rms. Temperature regulation is achieved by lowering the capillary into a dry gas stream that flows through a narrow slit in a wide aluminum nozzle whose temperature is controlled by two thermoelectric modules (TEMs) that transfer heat between the nozzle and coolant flowing through a heatsink. Rapid thermal equilibration between the capillary and nozzle occurs primarily through conductive heat exchange with the flowing gas. The performance of the temperature controller is well described by a heat-transfer model, with low heat-capacity components enabling fast temperature slew rates. The temperature-control head is compact and can be fitted with customizable apertures suitable for visual access to the capillary and for transmitting focused electromagnetic radiation through it. However, the thermal cycling of the TEMs at high operating temperatures led to the rapid degradation of their cooling capacity. To mitigate this issue, separate low-(∼4 °C), room-, and high-temperature (∼85 °C) coolant reservoirs and pinch valves were used to select the coolant reservoir based on the target temperature, thereby limiting the maximum temperature experienced across the TEMs during thermal cycling and dramatically extending their operational lifetime. This apparatus was designed primarily for temperature-dependent, time-resolved x-ray scattering studies of biomolecules in solution but has also been used in time-resolved spectroscopic investigations.

The number of deaths due to cardiovascular diseases has been steadily increasing, with the majority occurring in underdeveloped regions. Doctors in less developed regions often have limited clinical experience to diagnose these diseases by listening heart sounds, whereas artificial intelligence can serve as a valuable tool to assist them in conducting auxiliary diagnoses. However, small samples and strong noise reduce the diagnosis accuracy. Therefore, in this paper, a novel method is put forward for heart sound classification, which integrates sample augmentation and injected noise dual attention networks (INDANet). First of all, the heart sounds are preprocessed through a Butterworth filter to eliminate noise outside the cardiac frequency range. Then, a sample augmentation is utilized to increase the size of sample set. In addition, a suitable dose of Gaussian noise is injected to improve the robustness and generalization of INDANet with channel and spatial attention mechanism. Experiments on two datasets demonstrate that the proposed method achieves superior performance in heart sound classification compared to the other six advanced models. The accuracy in the two datasets achieves as high as 99.85% and 98.07%, respectively.