Compact ion/electron analyzer for spaceflight or laboratory use

One of the most popular approaches to improve the performance of organic photonic devices has been to control the electrically heterogeneous charge-transferring interfaces via chemical modifications. Despite intense research efforts, however, the rapid pace of material evolution through the chemical versatility of the organic compound allows only limited room for the fine-tuning of the interfaces exclusive to specific materials. This limitation leads to an ill-controlled charge recombination behavior that relies solely on the inherent characteristics of each material; thus, the common device architecture cannot harness its full potential. In this work, we demonstrate the use of a graphene-organic hybrid barristor-type phototriode architecture as an alternative platform to realize a linearly and highly photosensitive photodetector operating in a broad dynamic range with rapid temporal responses. With the capability of interfacial energetic modulation, our model system exhibits the dominance of swiftly saturable and slowly responding "cold" traps (TC < 3kT) in charge recombination behaviors, leading to a broad linear dynamic range of 110 dB as well as unconventional illumination-driven increments of both D* and R up to 1013 Jones and 360 mA/W, respectively, that surpass the best-reported organic photodiodes. Our findings demonstrate that the organic-graphene hybrid photonic barristor architecture can open new avenues to design high-performance photodetectors for various photonic applications in the future.

과학위성 1호의 주탑재체인 원자외선 분광기의 검출기 전자부에 대한 특성을 분석하였다. FIMS (Far-ultraviolet Imaging Spectrograph)는 교차 지연선 양극을 가진 MCP(micro-channel plate)를 사용하여 입사된 원자외선 광자의 위치를 검출한다. MCP에 입사하는 광자는 MCP을 통해 전자형태로 변환되고 증폭된다. 증폭된 전하운의 중심은 양분되어 연결된 지연선을 통해 양단으로 나가게 되고, 지연선의 양단에서 전하운의 도착시간 차이를 구하여 입사된 광자의 위치를 판독한다. FIMS의 경우 2개의 MCP 검출기를 갖고 있으며, 각각 25mm<TEX>$\times$</TEX>25mm의 유효 크기를 갖고있다. 또 신호처리계는 1채널의 신호처리 회로계를 통해 2개의 검출기에 대한 영상검출이 가능하도록 함으로써 신호처리계의 복잡성을 피하고 아울러 전력과 무게 비용을 줄였다. 이 시스템을 통해 높은 시간 및 공간 분해능(<<TEX>$35{\times}75$</TEX>ps FWHM)을 얻었으며, 6W 이하의 저전력 시스템을 구현하였다. We describe some performance of the detector electronics system for the FIMS (Far-ultraviolet Imaging Spectrograph) mission. The FIMS mission to map the far ultraviolet sky uses MCP (micro-channel plate) detectors with a crossed delay line anode to record photon arrival events. FIMS has two MCP detectors, each with a ~25mm<TEX>$\times$</TEX>25mm active area. The unconventional anode design allows for the use of a single set of position encoding electronics for both detector fields. The centroid position of the charge cloud, generated by the photon-stimulated MCP, is determined by measuring the arrival times at both ends of the anode following amplification and external delay. The temporal response of the detector electronics system determines the readout's positional resolution for the charge centroid. High temporal resolution (<<TEX>$35{\times}75$</TEX>ps FWHM) and low power consumption (< 6W) were achieved for the FIMS detector electronics system.

X-ray detection characteristics of gold photocathodes and microchannel plates using synchrotron radiation (10 eV–82.5 keV)

Protein chips are widely used for high-throughput proteomic analysis, but to date, the low sensitivity and narrow dynamic range have limited their capabilities in diagnostics and proteomics. Here we present protein microarrays on a novel nanostructured, plasmonic gold film with near-infrared fluorescence enhancement of up to 100-fold, extending the dynamic range of protein detection by three orders of magnitude towards the fM regime. We employ plasmonic protein microarrays for the early detection of a cancer biomarker, carcinoembryonic antigen, in the sera of mice bearing a xenograft tumour model. Further, we demonstrate a multiplexed autoantigen array for human autoantibodies implicated in a range of autoimmune diseases with superior signal-to-noise ratios and broader dynamic range compared with commercial nitrocellulose and glass substrates. The high sensitivity, broad dynamic range and easy adaptability of plasmonic protein chips presents new opportunities in proteomic research and diagnostics applications.

The research on key techniques of wide field extreme ultraviolet( EUV) spherical micro-channel plate( MCP) photon-counting imaging detector which will be used in space probe in China have been done.Firstly,the secondary electron yield model of photocathode material was built,and the secondary yield of alkali halide and MCP in soft X-ray and EUV band were calculated using the model. The measurement equipment of MCP's quantum detection efficiency also was set up. The calculated fomula of MCP' s quantum efficiency was introduced,and MCP's quantum efficiency vs. wavelength and incidence angle in soft X-ray and EUV region were measured. secondly,the instrument of solid core spherical MCP fabrication was established,a set ofspherical MCP with 150 mm radius were made using the instrument. The 48 mm induced charge wedge and strip anode in effective diameter was made by the use of traditional UV lithography,and the photon-counting imaging detector was integrated based on the anode and spherical MCP stack in Z configuration. Thirdly,the position readout electronics including analog frent-end and digital processing circuit and the software with image distortion rectification and real-time collection were developed. Finally,the measurement instrument of spherical MCP detector's spatial resolution and image linearity was built,and the specifications of the detector were measured using the instrument,showing that all technical specificaions of the detector satisfy the design requirements.

The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles' impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5-58 MeV carbon ions and for protons in the energy range 2-17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.

The EUV grating spectrograph (EGS) as part of the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) solar EUV experiment (SEE) presents a number of performance challenges for its microchannel plate (MCP)- based detector. The EGS measures the solar spectral irradiance from 25 to 200 nm. The intensities of the line and continuum emissions over this spectral range vary by up to five orders of magnitude. While a variety of transmission filters are strategically used to bring the signal over the entire spectrum into the dynamic range of a single chevron pair of MCPs, a number of concerns regarding the characteristic behavior of MCPs remain. The nominal TIMED mission is two years while the extended mission potentially doubles to four years. Over this period, the MCP response is expected to change to some extent. Detailed changes in MCP performance are notoriously application dependent,however. In order to better anticipate and accommodate these changes over the duration of the mission as well as to potentially enhance detector performance, we are performing a series of life-tests on a variety of MCPs. In these tests we characterize MCP gain, pulse height distribution, quantum detection efficiency, and linearity as function of accumulated charge and exposure to atmosphere. Here we report on the result of these test.s

The microchannel plate (MCP) is a semiconducting glass plate containing an array of open channels that can provide photo-electron amplification for imaging applications. Conventional MCP channel geometries are designed to inhibit ion-feedback that occurs in straight channel plates at high applied potentials. Ion-feedback must be reduced as much as possible since its presence degrades the performance of the plate by adding noise to the plate's output. The performance characteristics of a new geometrical design for a high-gain MCP, that employs channels that spiral downward in a helical fashion to inhibit ion-feedback, have been evaluated in the laboratory. A Multi-Anode Microchannel Array (MAMA) detector was used to test the new MCP. The "helical-channel" MCPs tested to date have channel diameters of 50 microns and have demonstrated stable operation at gains above 106 electrons/pulse. The goal of the program is to develop "helical-channel" MCPs with channel diameters as small as 12 microns within two years. Detailed performance data including the dynamic range, pulse-height distribution, and gain characteristics of this new MCP will be presented.

Objective To develop an assay of PCR-produet direct sequencing to detect hepatitis B virus (HBV) YMDD mutation, and compare the results gained by the sequencing and traditional real-time fluorescent PCR assays. Methods Serum samples were collected from 103 patients with chronic hepatitis B. HBV DNA were extracted from sers. YMDD mutation was detected by a commercial real-time PCR assay. Meanwhile, HBV reverse transcriptase-encoding gene was amplified by a nested PCR assay. The PCR products were directly subjected to sequencing at two directions, and the sequencing results were analyzed by NTI program. Using Kappa test, comparison was made between the results of rtM204-site mutations obtained by the direct sequencing and YMDD mutations by the real-time fluorescent PCR. Results The direct sequencing assay proved to be highly effective with bread range of detection in viral load from 500 to 1010copies/ml. And it may simultaneously avoid inhibitory effect caused by high viral load. The coincidence rates between two assays were 100% for YIDD, 97. 1% for YVDD, 76. 2% for YIDD/YVDD coexistence (Kappa = 0. 853, P < 0. 01). Conclusions The direct sequencing assay for HBV drug-resistant mutation detection is highly sensitive with broad dynamic range. It has high coincidence rate with real-time fluorescent PCR assay with advantage of detecting YMDD, YIDD and YVDD mutations simultaneously. Key words: Hepatitis B virus; Sequence analysis, DNA; Polymerase chain reaction; Mutation

Introduction: Here, we demonstrate Protein Identification by Short-epitope Mapping (PrISM), which aims to provide comprehensive proteome analysis with broad dynamic range at single-molecule resolution by interrogating immobilized, intact proteins in parallel using multi-affinity probes. Improving the dynamic range and scale for protein analyses will enable a deeper understanding of low abundant protein in all stages of cancer progression. In addition, enabling the interrogation of single-molecules will provide a deeper understanding of protein diversity, such as the proteoforms resulting from non-canonical post-translational modifications inherent to cancer1. The combination of single-molecule sensitivity with comprehensive proteome coverage could also open the door for highly sensitive and specific diagnostics. Methods: PrISM uses non-traditional affinity reagents with high affinity and low specificity that bind to short epitopes in multiple proteins. Sample proteins were conjugated to DNA nanoparticles and deposited on a high-density patterned flow cell at optically resolvable locations. Multi-affinity probes were applied to sample proteins over multiple cycles to generate binding patterns for each single-molecule protein, which are translated to protein identifications and quantities using a custom machine learning approach. We acquired PrISM data on native biological and control samples using dozens of multi-affinity probes targeting trimer or tetramer sequences. Results: We report single-molecule deposition of over 1 billion DNA nanoparticle complexes on a flow cell. We demonstrate how the PrISM methodology identifies individual protein molecules through iterative probing with our multi-affinity probes. Further, we provide an analytical assessment of the sensitivity and specificity of PrISM and demonstrate the ability to accurately estimate the false identification rate of these proteins using a target-decoy based statistical approach. Conclusions: Combining single-molecule analysis, intact (non-digested) proteins, and iterative probing, PrISM provides a new tool for quantitative proteomics. We demonstrate linear and reproducible quantification of proteins using PrISM, potentially enabling detection of low abundant proteins and proteoforms associated with cancer. The ability to make comprehensive measurements of intact proteins at single-molecule resolution could accelerate basic cancer research through to the clinic.

Antibody detection is crucial for monitoring host immune responses to specific pathogen antigens (Ags) and evaluating vaccine efficacies. The luciferase immunoprecipitation system (LIPS) was developed for sensitive detection of Ag-specific antibodies in sera from various species. In this study, we describe NanoLIPS, an improved LIPS assay based on NanoLuciferase (NLuc), and employ the assay for monitoring antibody responses following influenza virus infection or vaccination. We generated recombinant influenza virus hemagglutinin (HA) proteins tagged with N-terminal (N-NLuc-HA) or C-terminal (C-NLuc-HA) NLuc reporters. NLuc-HA yielded an at least 20-fold higher signal-to-noise ratio than did a LIPS assay employing a recombinant HA-Gaussia princeps luciferase (GLuc) fusion protein. NanoLIPS-based detection of anti-HA antibodies yielded highly reproducible results with a broad dynamic range. The levels of antibodies against C-NLuc-HA generated by mice vaccinated with recombinant vaccinia virus DIs strain expressing an influenza virus HA protein (rDIs-HA) was significantly correlated with the protective effect elicited by the rDIs-HA vaccine. C-NLuc-HA underwent glycosylation with native conformations and assembly to form a trimeric structure and was detected by monoclonal antibodies that detect conformational epitopes present on the globular head or stalk domain of HA. Therefore, NanoLIPS is applicable for evaluating vaccine efficacy. We also showed that C-NLuc-HA is applicable for detection of HA-specific antibodies in sera from various experimental species, including mouse, cynomolgus macaque, and tree shrew. Thus, NanoLIPS-based detection of HA offers a simple and high-sensitivity method that detects native conformational epitopes and can be used in various experimental animal models.IMPORTANCE Influenza virus HA-specific antibodies can be detected via the hemagglutination inhibition (HI) assay, the neutralization (NT) assay, and the enzyme-linked immunosorbent assay (ELISA). However, these assays have some drawbacks, including narrow dynamic range and the requirement for large amounts of sera. As an alternative to an ELISA-based method, luciferase immunoprecipitation system (LIPS) was developed. We focused on NanoLuciferase (NLuc), which has a small size, higher intensity, and longer stability. In this study, we developed a technically feasible and highly sensitive method for detecting influenza virus-specific antibodies using a NLuc-tagged recombinant HA protein produced in mammalian cells. HA with a C-terminal NLuc extension (C-NLuc-HA) was glycosylated and formed trimeric complexes when expressed in mammalian cells. Furthermore, C-NLuc-HA was recognized not only by monoclonal antibodies that bind to the globular head domain but also by those that bind to the stalk domain. We also demonstrated that the data obtained by this assay correlate with the protection of an experimental vaccine in animal models.

It has been proven (see for instance [1–11] that dielectric spectroscopy is a useful tool to study the molecular dynamics of polymers. This is due to the fact that a broad dynamical range from the milli- to the Giga-Hertz region can be covered by this method in its modern form (see Chap. 2). Therefore motional processes which take place for polymeric systems on extremely different time scales can be investigated in a broad frequency and temperature range. Moreover the motional processes depend on the morphology and micromorphology of the system under investigation. Therefore information on the structural state of the material can be indirectly extracted by taking the molecular mobility as a probe for the structure.

An optical fiber curvature sensor based on a no-core fiber (NCF) cascaded with a hollow-core fiber (HCF), realizing simultaneously high sensitivity and a broad dynamic range with the assistance of machine learning analysis is demonstrated.

This paper presents a broadband predistortion technique using dual-gate FETs to linearize the Traveling Wave Tube Amplifiers (TWTA) and Solid State Power Amplifiers (SSPA) used in satellite transponders. The results for a linearized TWTA operating over 11.7-12.2 GHz and a linearized SSPA operating over 3.8-4.2 GHz are presented. The improvement in linearity has been achieved over a broad dynamic range of output power.

A luminescent probe for determination of pH was designed based on a Förster resonance energy transfer (FRET) system, combining a europium chelate as the donor and carboxynaphtho-fluorescein as a pH sensitive acceptor. The FRET system enables referenced pH detection in an exceptional broad dynamic range from pH 3 to 9.