- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Optimization of X-ray image acquisition and reconstruction for a C-arm CBCT system with a flat-panel detector
摘要： A modern cone-beam computed tomography (CBCT) system with a C-arm gantry incorporating a large-area flat-panel detector is an important imaging tool widely used for diagnosis and image-guidance in spine surgery, orthopedic and interventional suite, and image-guided radiation therapy. In this study, the experimental prototype CBCT imaging platform consists of a benchtop system that is integrated with a cone-beam X-ray tube, a collimator, an anti-scatter grid, and a large-area TFT-based flat-panel detector. The different projection images in the C-arm CT system were usually acquired at short scanning angles with a constant interval for various exposure conditions. The performance of CT imaging quality was performed using the Feldkamp, Davis and Kress (FDK) reconstruction algorithm through acquired two-dimensional projection images at different scanning angles and projection numbers. Quantitative analysis of the image quality was performed by using the cone-beam CT phantom for spatial resolution, low-contrast resolution, noise, and two different phantoms, such as the head and pelvis.
关键词： Flat-panel X-ray detector,3D image reconstruction,Cone-beam CT system,C-arm CT system
更新于2025-09-23 15:23:52
-
Pixel-to-pixel variation on a calibrated PILATUS3-based multi-energy soft x-ray detector
摘要： A multi-energy soft x-ray pin-hole camera based on the PILATUS3 100 K x-ray detector has recently been installed on the Madison Symmetric Torus. This photon-counting detector consists of a two-dimensional array of ～100 000 pixels for which the photon lower-threshold cutoff energy Ec can be independently set for each pixel. This capability allows the measurement of plasma x-ray emissivity in multiple energy ranges with a unique combination of spatial and spectral resolution and the inference of a variety of important plasma properties (e.g., T e, nZ, Z eff). The energy dependence of each pixel is calibrated for the 1.6–6 keV range by scanning individual trimbit settings, while the detector is exposed to ?uorescence emission from Ag, In, Mo, Ti, V, and Zr targets. The resulting data for each line are then ?t to a characteristic "S-curve" which determines the mapping between the 64 possible trimbit settings for each pixel. The statistical variation of this calibration from pixel-to-pixel was explored, and it was found that the discreteness of trimbit settings results in an effective threshold resolution of ?E < 100 eV. A separate calibration was performed for the 4–14 keV range, with a resolution of ?E < 200 eV.
关键词： energy calibration,x-ray detector,photon-counting,multi-energy soft x-ray,plasma x-ray emissivity,PILATUS3
更新于2025-09-23 15:21:21
-
Three-dimensional Lead Iodide Perovskitoid Hybrids with High X-ray Photoresponse
摘要： Large organic A cations cannot stabilize the 3D perovskite AMX3 structure because they cannot be accommodated in the cubo-octhedral cage (do not follow the Goldschmidt tolerance factor rule), and they generally template low-dimensional structures. Here we report that the large di-cation aminomethylpyridinium (AMPY), can template novel 3D structures which resemble conventional perovskites. They have the formula (xAMPY)M2I6 (x = 3 or 4, M = Sn2+ or Pb2+) which is doubled the AMX3 formula. However, because of the steric requirement of the Goldschmidt tolerance factor rule, it is impossible for (xAMPY)M2I6 to form proper perovskite structures. Instead, a combination of corner-sharing and edge-sharing connectivity is adopted in these compounds leading to the new 3D structures. DFT calculations reveal that the compounds are indirect-bandgap semiconductors with direct bandgaps presenting at slightly higher energies and dispersive electronic bands. The bandgaps of the Sn and Pb compounds are ~ 1.7 eV and 2.0 eV, respectively, which is slightly higher than the corresponding AMI3 3D perovskites. The Raman spectra for the compounds are diffuse, with a broad rising central peak at very low frequencies around 0 cm-1, a feature that is characteristic of dynamical lattices, highly anharmonic, and dissipative vibrations very similar to the 3D AMX3 perovskites. Devices of (3AMPY)Pb2I6 crystals exhibit clear photoresponse under ambient light without applied bias, reflecting a high carrier mobility (μ) and long carrier lifetime (τ). The devices also exhibit sizable X-ray generated photocurrent with a high μτ product of ~1.2×10-4 cm2 /V and an X-ray sensitivity of 207 μC·Gy-1·cm-2.
关键词： Metal halide hybrids,mixed cations,photoresponse,X-ray detector,anomalous bandgap behavior
更新于2025-09-23 15:19:57
-
Enhanced X-ray sensitivity of MAPbBr3 detector by tailoring the interface-states density
摘要： An important factor for the high performance of light-harvesting devices is the presence of surface trappings. Therefore, understanding and controlling the carrier recombination of the organic-inorganic hybrid perovskite surface is critical for the device design and optimization. Here, we report the use of aluminum zinc oxide (AZO) as the anode to construct a p-n junction structure MAPbBr3 nuclear radiation detector. The AZO/MAPbBr3/Au detector can tolerate an electrical field of 500 V·cm-1 and exhibit a very low leakage current of ~9 nA, which is one order of magnitude lower than that of the standard ohmic contact device. The interface state density of AZO/MAPbBr3 contact was reduced from 2.17×1010 cm-2 to 8.7×108 cm-2 by annealing at 100 °C under Ar atmosphere. Consequently, a photocurrent to dark current ratio of 190 was realized when exposed to a green LED with a wavelength of 520 nm (~200 mW·cm?2). Simultaneously, a high X-ray sensitivity of ~529 μC·Gyair-1cm-2 was achieved under 80 kVp X-ray at an electric field of 50 V·cm-1. These results demonstrate the use of surface engineering to further optimize the performance of MAPbBr3 detectors, which have many potential applications in medical and security detection with low radiation dose brought to the human body.
关键词： p-n junction,annealing,X-ray detector,MAPbBr3 PSC,interface states density
更新于2025-09-19 17:15:36
-
Sensitivity Improvement of Quantum Dot-Blended Hybrid Detector for X-ray Imaging
摘要： This study investigated the characteristics of an indirect-type hybrid X-ray detector with a conjugated polymer poly(3-hexylthiophene) (P3HT) and CdSe quantum dot (QD) blended active layer. To improve detection sensitivity, the optimal blending ratio of P3HT:CdSe QDs, ligand exchange effect, and optimal process condition of the active layer were examined. The detector with a P3HT:CdSe QDs = 1:5 blended active layer showed the highest collected charge density (CCD) and highest sensitivity under X-ray irradiation. The replacement of a trioctylphosphine (TOP) ligand by a pyridine ligand effectively assisted the charge transport and reduced the QD aggregation, increasing the detection sensitivity of the detector by 75% after the ligand exchange. To further improve the sensitivity of the proposed detector, the optimized process conditions of the active layer were studied. The sensitivity of the detector with an active layer of about 80 nm thickness formed by a double-coating method showed the highest CCD of 62.5 nA/cm2, and the highest sensitivity of 0.14 mA/Gy?cm2. Due to additional pyridine treatment between the double-coating processes, the surface roughness of the active layer decreased, and the CCD and sensitivity subsequently increased.
关键词： Quantum dots,hybrid detector,indirect X-ray detector,ligand exchange
更新于2025-09-16 10:30:52
-
Filterless Polarization‐Sensitive 2D Perovskite Narrowband Photodetectors
摘要： An important factor for the high performance of light-harvesting devices is the presence of surface trappings. Therefore, understanding and controlling the carrier recombination of the organic?inorganic hybrid perovskite surface is critical for the device design and optimization. Here, we report the use of aluminum zinc oxide (AZO) as the anode to construct a p?n junction structure MAPbBr3 nuclear radiation detector. The AZO/MAPbBr3/Au detector can tolerate an electrical field of 500 V·cm?1 and exhibit a very low leakage current of ～9 nA, which is 1 order of magnitude lower than that of the standard ohmic contact device. The interface state density of AZO/MAPbBr3 contact was reduced from 2.17 × 1010 to 8.7 × 108 cm?2 by annealing at 100 °C under an Ar atmosphere. Consequently, a photocurrent to dark current ratio of 190 was realized when exposed to a green light-emitting diode with a wavelength of 520 nm (～200 mW·cm?2). Simultaneously, a high X-ray sensitivity of ～529 μC·Gyair?1 cm?2 was achieved under 80 kVp X-ray at an electric field of 50 V·cm?1. These results demonstrate the use of surface engineering to further optimize the performance of MAPbBr3 detectors, which have many potential applications in medical and security detection with low radiation dose brought to the human body.
关键词： p?n junction,X-ray detector,interface state density,MAPbBr3 PSC,annealing
更新于2025-09-11 14:15:04
-
P-6.11: Sensor Technology - A new chance for low generation TFT production line
摘要： We analyzed several sensor technology which have good compatibility with current TFF process, including Digital X-Ray Detector, Glass-substrate Pressure Sensor, Glass-substrate Memory, Glass-substrate Antenna and Glass-substrate MEMS Devices. The above offers some directions for low generation TFT production line’s transition.
关键词： Glass-substrate Memory,Digital X-Ray Detector,Glass-substrate MEMS Devices,Glass-substrate Pressure Sensor,Glass-substrate Antenna
更新于2025-09-09 09:28:46
-
Three-strip microchannel plate gated x-ray framing camera
摘要： A microchannel plate (MCP) gated x-ray framing camera with three-strip is reported. The diameter of the MCP is 56 mm and the width of each microstrip line cathode deposited on the MCP is 8 mm. While the microstrip line cathode is driven by a gating electrical pulse with width of 200 ps and amplitude of ?1.9 kV overlapped with a ?200 V DC bias, the measured temporal resolution is about 68 ps. Furthermore, the gain uniformity of the microstrip line cathode is measured showing that there is a 3.6× drop in gain along the pulse propagation direction, whereas the variations in the gain transverse to the pulse propagation direction are within 10%.
关键词： X-ray detector,Temporal resolution,Framing camera,Gain uniformity
更新于2025-09-04 15:30:14
-
High-Quality Cuboid CH <sub/>3</sub> NH <sub/>3</sub> PbI <sub/>3</sub> Single Crystals for High Performance X-Ray and Photon Detectors
摘要： Organic–inorganic halide hybrid perovskite materials are promising materials for X-ray and photon detection due to their superior optoelectronic properties. Single-crystal (SGC) perovskites have increasingly attracted attention due to their substantially low crystal defects, which contribute to improving the figures of merit of the devices. Cuboid CH3NH3PbI3 SGC with the naturally favorable geometry for device fabrication is rarely reported in X-ray and photon detection application. The concept of seed dissolution-regrowth to improve crystal quality of cuboid CH3NH3PbI3 SGC is proposed and a fundamental understanding of the nucleation and growth is provided thermodynamically. The X-ray detector fabricated from cuboid CH3NH3PbI3 SGC demonstrates the firstly reported high sensitivity of 968.9 μC?1 Gy?1 cm?2 under ?1 V bias. The results also show that the favorable crystal orientation and high quality of cuboid CH3NH3PbI3 leads to better responsivity and faster response speed than the more common dodecahedral CH3NH3PbI3 in photodetection. Consequently, the work paves a way to synthesize high-quality perovskite SGCs and benefits the application of MAPbI3 SGCs with preferred crystal orientation and favorable crystal geometry for emerging device applications.
关键词： photodetector,cuboid,single crystal,perovskite,X-ray detector
更新于2025-09-04 15:30:14