Track Imaging System Research Articles

A proton-recoil track imaging system for fast neutrons: the RIPTIDE detector

Fast neutron detection is often based on the neutron-proton elastic scattering reaction: the ionization caused by recoil protons in a hydrogenous material constitutes the basic information for the design and development of a class of neutron detectors. Although experimental techniques have continuously improved, proton-recoil track imaging remains still at the frontier of n-detection systems, due to the high photon sensitivity required. Several state-of-the-art approaches for neutron tracking by using n-p single and double scattering — referred to as Recoil Proton Track Imaging (RPTI) — can be found in the literature. So far, they have showed limits in terms of detection efficiency, complexity, cost, and implementation. In order to address some of these deficiencies, we propose the design of RIPTIDE, a novel recoil-proton track imaging detector in which the light output produced by a fast scintillator is used to perform a complete reconstruction in space and time of the interaction events. The proposed idea is viable thanks to the dramatic advances in low noise and single photon counting achieved in the last decade by new scientific CMOS cameras as well as pixel sensors, like Timepix or MIMOSIS. In this contribution, we report the advances on the RIPTIDE concept: Geant4 Monte Carlo simulations, light collection tests as well as state-of-the-art approach to image readout, processing and fast analysis.

A Tracking Imaging Control Method for Dual-FSM 3D GISC LiDAR

In this paper, a tracking and pointing control system with dual-FSM (fast steering mirror) composite axis is proposed. It is applied to the target-tracking accuracy control in a 3D GISC LiDAR (three-dimensional ghost imaging LiDAR via sparsity constraint) system. The tracking and pointing imaging control system of the dual-FSM 3D GISC LiDAR proposed in this paper is a staring imaging method with multiple measurements, which mainly solves the problem of high-resolution remote-sensing imaging of high-speed moving targets when the technology is transformed into practical applications. In the research of this control system, firstly, we propose a method that combines motion decoupling and sensor decoupling to solve the mechanical coupling problem caused by the noncoaxial sensor installation of the FSM. Secondly, we suppress the inherent mechanical resonance of the FSM in the control system. Thirdly, we propose the optical path design of a dual-FSM 3D GISC LiDAR tracking imaging system to solve the problem of receiving aperture constraint. Finally, after sufficient experimental verification, our method is shown to successfully reduce the coupling from 7% to 0.6%, and the precision tracking bandwidth reaches 300 Hz. Moreover, when the distance between the GISC system and the target is 2.74 km and the target flight speed is 7 m/s, the tracking accuracy of the system is improved from 15.7 μrad (σ) to 2.2 μrad (σ), and at the same time, the system recognizes the target contour clearly. Our research is valuable to put the GISC technology into practical applications.

RIPTIDE: a novel recoil-proton track imaging detector for fast neutrons

Neutron detectors are an essential tool for the development of many research fields, as nuclear, particle and astroparticle physics as well as radiotherapy and radiation safety. Since neutrons cannot directly ionize, their detection is only possible via nuclear reactions. Consequently, neutron-based experimental techniques are related to the detection of charged particle or electromagnetic radiation originating from neutron-induced reactions. The study of fast neutrons is often based on the neutron-proton elastic scattering reaction. In this case, the ionization induced by the recoil protons in a hydrogenous material constitutes the basic information for the design and development of neutron detectors. Although experimental techniques have continuously improved and refined, so far, proton-recoil track imaging is still weak in laboratory rate environments because of the extremely small detection efficiency. To address this deficiency, we propose a novel recoil-proton track imaging system in which the light deriving from a fast scintillation signal is used to perform a complete reconstruction in space and time of the event. In particular, we report the idea of RIPTIDE (RecoIl Proton Track Imaging DEtector): an innovative system which combines a plastic scintillator coupled to imaging devices, based on CMOS technology, or micro channel plate sensors. The proposed apparatus aims at providing neutron spectrometry capability by stereoscopically imaging the recoil-protons tracks, correlating the spatial information with the time information. RIPTIDE intrinsically enable the online analysis of the ionization track, thus retrieving the neutron direction and energy, without spoiling the overall efficiency of the detection system. Finally, the spatial and topological event reconstruction enables particle discrimination — a crucial requirement for neutron detection — by deducing the specific energy loss along the track.

Recoil-proton track imaging as a new way for neutron spectrometry measurements

Recoil-proton track imaging (RPTI) is an attractive technique to optically record the tracks of recoil protons in scintillation gas by using realtime imaging devices. For the first time, its use as an online nuclear track detector for neutron spectrometry measurements (NSM) is explored. Based on the RPTI methodology for NSM, a very basic detector system is designed, consisting of the neutron-to-proton recoil system and proton track imaging system. Satisfactory performance of the RPTI neutron spectrometer has been examined with a series of Monte Carlo simulations. Moreover, using well-defined line-proton sources from a tandem accelerator, the capability of the detector for imaging proton tracks at the single-particle level in real time has been validated in preliminary experiments. From the clear single proton tracks in the images, the proton ranges were easily distinguished, and precise proton energy spectra were unfolded, laying a solid experimental foundation for the future implementation of NSM.

高定位精度三维动态追踪成像系统研究及应用

高定位精度三维动态追踪成像系统研究及应用

Atorvastatin can ameliorate left atrial stunning induced by radiofrequency ablation for atrial fibrillation.

The objective of this study was to study the functional changes of the left atrium after radiofrequency ablation treatment for atrial fibrillation and the therapeutic effect of atorvastatin. Fifty-eight patients undergoing radiofrequency ablation for atrial fibrillation were randomly divided into non-atorvastatin group and atorvastatin group. Patients in the atorvastatin group were treated with atorvastatin 20 mg p.o. per night in addition to the conventional treatment of atrial fibrillation; patients in the non-atorvastatin group received conventional treatment of atrial fibrillation only. Echocardiography was performed before radiofrequency ablation operation and 1 week, 2 weeks, 3 weeks, and 4 weeks after operation. Two-dimensional ultrasound speckle tracking imaging system was used to measure the structural indexes of the left atrium. Results indicated that there was no significant change for indexes representing the structural status of the left atrium within a month after radiofrequency ablation (P > 0.05); however, there were significant changes for indexes representing the functional status of the left atrium. There were also significant changes in indexes reflecting left atrial strain status: the S and SRs of atorvastatin group were higher than those of non-atorvastatin group (P < 0.05). In summary, atorvastatin could improve left atrial function and shorten the duration of atrial stunning after radiofrequency ablation of atrial fibrillation.

Research on target tracking capture rate calculation and target optical characteristic in target optical imaging tracking system

ABSTRACTBased on the instability problem of target tracking performance in the optical tracking imaging system of field operations, this article researches the target tracking capture rate. The target tracking platform is established with target imaging radiation characteristics and target movement features and target optical properties are researched with photometry knowledge. According to target detection range, target size, environmental illumination and area array CCD imaging characteristics, the calculation model of target tracking capture rate is deduced and the factors that affecting the target capture rate are analyzed. By calculation and experimental analysis, the target capture rate decreases when the detection range increases and the target capture rate increases when the target size is larger. The target gray value is relatively stable when the weather is sunny and target images captured by CCD are given when the target size is . The optical imaging system can work day and night and the target capture rate can get 95% with the laser strobe auxiliary illumination technology. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2672–2677, 2016

A novel track imaging system as a range counter

An image-intensified, camera-based track imaging system has been developed to measure the tracks of ions in a scintillator block. To study the performance of the detector unit in the system, two types of scintillators, a dosimetrically tissue-equivalent plastic scintillator EJ-240 and a CsI(Tl) scintillator, were separately irradiated with carbon ion (12C) beams of therapeutic energy from HIMAC at NIRS. The images of individual ion tracks in the scintillators were acquired by the newly developed track imaging system. The ranges reconstructed from the images are reported here. The range resolution of the measurements is 1.8mm for 290MeV/u carbon ions, which is considered a significant improvement on the energy resolution of the conventional ΔE/E method. The detector is compact and easy to handle, and it can fit inside treatment rooms for in-situ studies, as well as satisfy clinical quality assurance purposes.

Abstract 18017: Validations for the Reliability of a Dedicated 3-Dimensional Speckle Tracking Imaging System for Right Ventricular Function Analysis

Background: Three-dimensional (3D) imaging has the potential to evaluate right ventricular (RV) function accurately because of its complex geometry. We have developed a dedicated 3D-speckle tracking imaging (STI) system for the right ventricle, and performed validation studies to assess the reliability of 3D-STI derived deformation data. Methods: In 9 anesthetized sheep, RV full volume data sets for 3D-STI were obtained using a 3D echocardiography system (Toshiba Medical Systems) simultaneously with sonomicrometry data at the baseline and during pulmonary artery (PA) banding at moderate and severe levels, and propranolol infusion. In 7 RV segments (basal and mid anterior, basal and mid lateral, basal and mid inferior, and outflow), area change ratio (ACR), longitudinal strain (LS), and circumferential strain (CS) were calculated with prototype 3D-STI software (Figures) and compared with those by sonomicrometry. Results: ACR by 3D-STI strongly correlated with sonomicrometry data (Y=0.78X-5.0, R=0.83, p&lt;0.001). LS and CS also showed significant correlations between the modalities (LS; Y=0.78X-1.8, R=0.79, CS; Y=0.62X-2.9, R=0.77, p&lt;0.001). In segmental analysis, all deformation data showed significant correlations in each segment. During PA banding, PA pressure increased at a moderate (48.4±8.4mmHg) and a severe level (53.9±8.5mmHg mmHg) compared to the baseline (22.5±4.6mmHg). In contrast, 3D-STI data had graded decreases at the baseline, moderate and severe levels (ACR; -32.5±8.3, -24.2±10.0, -16.1±10.9%, p&lt;0.001, LS; -16.0±6.2, -9.5±6.8, -5.1±7.7%, p&lt;0.001, CS; -16.3±5.4, -12.6±7.6, -9.3±7.3%, p=0.003). During propranolol infusion, RV dP/dt was significantly decreased compared to the baseline (807±287 vs. 535±199 mmHg/s, p=0.01), and 3D-STI data also reduced (ACR; -23.3±7.7, LS; -10.4±5.8, CS; -11.5±5.4, p&lt;0.05 vs. baseline). Conclusions: The newly developed 3D-STI system is a reliable modality for RV function analysis.

Near-intrinsic energy resolution for 30–662 keV gamma rays in a high pressure xenon electroluminescent TPC

We present the design, data and results from the NEXT prototype for Double Beta and Dark Matter (NEXT-DBDM) detector, a high-pressure gaseous natural xenon electroluminescent time projection chamber (TPC) that was built at the Lawrence Berkeley National Laboratory. It is a prototype of the planned NEXT-100 136Xe neutrino-less double beta decay (0νββ) experiment with the main objectives of demonstrating near-intrinsic energy resolution at energies up to 662keV and of optimizing the NEXT-100 detector design and operating parameters. Energy resolutions of ∼1% FWHM for 662keV gamma rays were obtained at 10 and 15atm and ∼5% FWHM for 30keV fluorescence xenon X-rays. These results demonstrate that 0.5% FWHM resolutions for the 2459keV hypothetical neutrino-less double beta decay peak are realizable. This energy resolution is a factor 7–20 better than that of the current leading 0νββ experiments using liquid xenon and thus represents a significant advancement. We present also first results from a track imaging system consisting of 64 silicon photo-multipliers recently installed in NEXT–DBDM that, along with the excellent energy resolution, demonstrates the key functionalities required for the NEXT-100 0νββ search.

A time projection chamber with optical readout for charged particle track structure imaging

We report about a nuclear track imaging system which is designed to study in detail the ionization topology of charged particle tracks in a low-pressure gas. The detection method is based on a time projection chamber (TPC) filled with low-pressure triethylamine (TEA). Ionization electrons produced by energetic charged particles are three-dimensionally imaged by recording light from electron avalanches with an intensified CCD system. The detector permits to investigate the spatial ionization distributions of particle tracks in gas, of equivalent length and resolution in tissue of 4 μm and 40 nm (RMS), respectively. We explain the relevance of this technique for dosimetry, describe the experimental method and the basic operation parameters. First results of the chamber response to protons and alpha particles are presented.

AGATE: A high energy gamma-ray telescope using drift chambers

The exciting results from the highly successful Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory (CGRO) has contributed significantly to increasing our understanding of high energy gamma-ray astronomy. A follow-on mission to EGRET is needed to continue these scientific advances as well as to address the several new scientific questions raised by EGRET. Here we describe the work being done on the development of the Advanced Gamma-Ray Astronomy Telescope Experiment (AGATE), visualized as the successor to EGRET. In order to achieve the scientific goals, AGATE will have higher sensitivity than EGRET in the energy range 30 MeV to 30 GeV, larger effective area, better angular resolution, and an extended low and high energy range. In its design, AGATE will follow the tradition of the earlier gamma-ray telescopes, SAS-2, COS B, and EGRET, and will have the same four basic components of an anticoincidence system, directional coincidence system, track imaging, and energy measurement systems. However, due to its much larger size, AGATE will use drift chambers as its track imaging system rather than the spark chambers used by EGRET. Drift chambers are an obvious choice as they have less deadtime per event, better spatial resolution, and are relatively easy and inexpensive to build. Drift chambers have low power requirements, so that many layers of drift chambers can be included. To test the feasibility of using drift chambers, we have constructed a prototype instrument consisting of a stack of sixteen 1/2m × 1/2m drift chambers and have measured the spatial resolution using atmospheric muons. The results on the drift chamber performance in the laboratory are presented here.