Design Of Detector System Research Articles

Coded aperture and Compton imaging capability of spherical detector system design based on GAGG scintillators: A Monte Carlo study

In the study of this paper, based on the symmetry of regular icosahedron, a spherical detector system for 4π field-of-view (FOV) gamma imaging was proposed based on 80 GAGG (Ce:GAGG, Gd3Al2Ga3O12) scintillator pixels. The spherical detector system combines both coded aperture (CA) and Compton imaging (CI) modalities. The detector system was simulated precisely with an experimental test of one representative GAGG pixel. Several radionuclides with characteristic energy ranging from 59.5 keV to 1.33 MeV were imaged under the far-field situation. Both imaging modes realize the 4π view while the coded aperture method achieves a higher image quality for radioactive sources with lower energy and the Compton method performs conversely. The imaging system can localize a 10 mCi 137Cs point source at 10 m within 1 s in the two modes and the Compton imaging mode reaches a high detection efficiency of up to 200 cps/μSv/h for 137Cs. And the angular estimation full-width-at-half-maximum (FWHM) was approximately 5.2°for coded aperture mode and 14°for Compton mode. The angular resolution was evaluated to be better than 30°. The high intrinsic imaging sensitivity and reasonable imaging quality make this detector system design attractive for far-field radiation imaging.

Coded Aperture and Compton Imaging Capability of Spherical Detector System Design Based on Gagg Scintillators

Coded Aperture and Compton Imaging Capability of Spherical Detector System Design Based on Gagg Scintillators

Coded Aperture and Compton Imaging Capability of Spherical Detector System Design Based on GAGG Scintillators

Coded Aperture and Compton Imaging Capability of Spherical Detector System Design Based on GAGG Scintillators

Review of superconducting nanowire single-photon detector system design options and demonstrated performance

We describe a number of methods that have been pursued to develop superconducting nanowire single-photon detectors (SNSPDs) with attractive overall performance, including three systems that operate with >70% system detection efficiency and high maximum counting rates at wavelengths near 1550 nm. The advantages and tradeoffs of various approaches to efficient optical coupling, electrical readout, and SNSPD design are described and contrasted. Optical interfaces to the detectors have been based on fiber coupling, either directly to the detector or through the substrate, using both single-mode and multimode fibers with different approaches to alignment. Recent advances in electrical interfaces have focused on the challenges of scalability and ensuring stable detector operation at high count rates. Prospects for further advances in these and other methods are also described, which may enable larger arrays and higher-performance SNSPD systems in the future. Finally, the use of some of these techniques to develop fully packaged SNSPD systems will be described and the performance available from these recently developed systems will be reviewed.

Detectors For Space Science

The design of detector systems for flight applications requires the consideration of a number of issues unique to space instrumentation. Flight detectors must endure hostile radiation environments and thermal extremes. Paramount importance is given to reliability since inflight replacement is at best difficult and usually impossible. Flight detectors are also significant cost and design drivers since they often determine key requirements for flight instruments such as volume, mass, power consumption, heat dissipation and communications budgets. In this paper we describe the primary concerns in developing flight detector systems, and review the challenges posed by future NASA and ESA space science missions for detector development.

The CMS muon system

An overview of the CMS Muon Detector System design and goals is made. The system includes several types of detectors. In the barrel part Drift Tube Chambers are used, whereas Cathode Strip Chambers have been chosen for the endcaps. The main features, and the performance, of both types of chambers are described. We also report on the current status of the production of these detectors.

Electromechanically cooled germanium radiation detector system

We have successfully developed and fielded an electromechanically cooled germanium radiation detector (EMC-HPGe) at Lawrence Livermore National Laboratory (LLNL). This detector system was designed to provide optimum energy resolution, long lifetime, and extremely reliable operation for unattended and portable applications. For most analytical applications, high purity germanium (HPGe) detectors are the standard detectors of choice, providing an unsurpassed combination of high energy resolution performance and exceptional detection efficiency. Logistical difficulties associated with providing the required liquid nitrogen (LN) for cooling is the primary reason that these systems are found mainly in laboratories. The EMC-HPGe detector system described in this paper successfully provides HPGe detector performance in a portable instrument that allows for isotopic analysis in the field. It incorporates a unique active vibration control system that allows the use of a Sunpower Stirling cycle cryocooler unit without significant spectral degradation from microphonics. All standard isotopic analysis codes, including MGA and MGA++ [1], GAMANL [2], GRPANL [3]and MGAU [4], typically used with HPGe detectors can be used with this system with excellent results. Several national and international Safeguards organisations including the International Atomic Energy Agency (IAEA) and U.S. Department of Energy (DOE) have expressed interest in this system. The detector was combined with custom software and demonstrated as a rapid Field Radiometric Identification System (FRIS) for the U.S. Customs Service [5]. The European Communities' Safeguards Directorate (EURATOM) is field-testing the first Safeguards prototype in their applications. The EMC-HPGe detector system design, recent applications, and results will be highlighted.

Development of Non-Intensified Charge-Coupled Device Area X-ray Detectors

Area X-ray detectors based on charge-coupled device imagers can provide excellent performance in terms of spatial resolution, sensitivity and dynamic range. Improvements in the fabrication of the primary converter, either scintillator or phosphor, mean that it is becoming possible to dispense with prestorage intensifiers and still provide outstanding low-level signal performance. Structured CsI scintillators are presented as one method of providing high efficiency and excellent spatial resolving power for this primary converter. Characterization of detector performance, in terms of such parameters as the detective quantum efficiency, point-spread function and dynamic range, needs to be directly related to the specific application of the detector. This contribution emphasizes the interplay of these parameters in the optimum design of detector systems. Performance prediction, based on measurements taken from prototype development systems, illustrates how such detectors will meet the exacting requirements of macromolecular crystallography.

Application of forward and adjoint Monte Carlo coupling technique to detector system designs

Forward and adjoint Monte Carlo coupling technique has been developed for analyzing neutron streaming in a system with large geometry. Particles (neutron and adjoint particle) are scored by surface type estimators such as the next event surface crossing estimators and the boundary crossing estimators. The detector response is calculated by folding the calculated neutron and adjoint angular fluxes. The reliability and efficiency for this method were studied by solving a sample problem of neutron streaming through narrow sodium pipe embedded in an iron shield. This method turned out to give a figure of merit several times better than the conventional method. The applicability of the method to detector system design has been demonstrated by calculating the signal to noise ratio for the fuel failure detector with delayed neutron detection method, which is located behind the reactor shield of concrete. This method gives an advantage in clarifying the spatial channels for neutron streaming.

The impact of microelectronics on particle detection

Progress in microelectronics has an impact on silicon detector manufacturing technology and on detector system design. Noise performance, miniaturization and lower cost of hybrid or integrated front-end electronics enable thinner, segmented silicon detectors to be used for a number of new applications.

Low Temperature Characteristics of Solid State Detectors for Energetic X-Ray, Ion and Electron Spectrometers

The low temperature characteristics of silicon surface barrier detectors have been investigated to obtain high resolution energetic particle and x-ray measurements for spacecraft applications. Relatively simple electrical and thermal coupling techniques were implemented such that large detector array concepts are feasible. For a 50 mm2 by 1.5 mm depletion depth surface barrier detector cooled to -80°C the x-ray resolution is 800 eV FWHM using an AC coupled spacecraft instrument preamplifier. Detector system design and calibration results are presented for a spacecraft instrument using both passive radiators and thermoelectric coolers. Energy loss rates in the dead zone region are given for energetic electrons with gold and aluminum surface deposits on the detectors.