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High spatial resolution thin CsI:Tl scintillator films was prepared by thermal deposition method for X-ray imaging applications. We fabricated CsI:Tl scintillators ranging from 2 μm to 14 μm in thickness. We measured spacial resolution and light yield as a function of input photons energy (5-40 keV) and film thickness. To improve spatial resolution...
Citations
... The thermal vapour deposition technique we used is described elsewhere [18] in the context of later developed luminophores specifically for X-ray imaging, so here we provide only a brief overview together with the differences. A mixture of CsI and Tl (doping concentration ∼0.08 mole%) was maintained at a temperature of 680 • C in a tantalum boat placed some 65 cm below the rotating, framemounted ultra-thin PET substrate. ...
... The deposition rate was kept low (17±2Å/s) in order to achieve an even coverage. The CsI(Tl) layer structure, when analyzed by a scanning electron microscope (SEM), was found to consist of grains between 2-5 µm in size [18]. ...
... µm thickness. None of the foils had a special surface coating added as mentioned in [18]. An example of such a frame-mounted foil is shown in Figure 1. ...
High-intensity secondary beams play a vital role in today's particle physics and materials science research and require suitable detection techniques to adjust beam characteristics to optimally match experimental conditions. To this end we have developed a non-invasive, ultra-thin, CsI(Tl) luminophore foil detector system, based on CCD-imaging. We have used this to quantify the beam characteristics of an intensity-frontier surface muon beam used for next-generation charged lepton-flavour violation (cLFV) search experiments at the Paul Scherrer Institut (PSI) and to assess the possible use for a future High-intensity Muon Beam (HiMB-project), currently under study at PSI. An overview of the production and intrinsic characteristics of such foils is given and their application in a high-intensity beam environment.
... Thus, intense research and development [2] [3] have continued, looking for new scintillation materials or the optimization of the current ones, taking advantage of new technological methods for their preparation. Understanding the underlying physical mechanisms of energy transfer and storage and the role of particular material defects is of crucial importance for bringing the materials performance close to their intrinsic limits. ...
The scintillator film, as a key element affecting X-ray detection imaging resolution, has attracted more and more attention. At present, it is mainly obtained by grinding and polishing of crystal or ceramic scintillators and film evaporation technology, with high cost, limited size and long preparation period. In this work, we propose a simple method to prepare scintillator films by blending (Lu0.995Ce0.005)3Al5O12 nano-powders and polydimethylsiloxane (PDMS), and characterize the uniformity, light absorption, photoluminescence, and X-ray excited luminescence (XEL) of these. The XEL results show that the prepared LuAG:Ce-PDMS composite scintillator films have a clear broadband emission in the region of 480 and 680 nm, which can be well coupled with silicon photodiodes. Its XEL integral intensity is 286% that of commercial BGO scintillators, and the spatial resolution is 25 lp/mm when the film thickness is 100 μm. All of those show the LuAG:Ce-PDMS composite scintillator films have a potential application in scintillator-based indirect-type X-ray imaging.
Zero-dimensional halide perovskite Cs3Cu2I5-based nanocrystals and bulk crystals have proven to be sensitive and efficient scintillators for X-ray and γ-ray detection. In this work, undoped and Tl-doped Cs3Cu2I5 microcrystalline films were synthesized by the thermal evaporation method. Both films crystallized into Pnma space group of orthorhombic crystal lattice with preferred (004) growth orientation. The undoped Cs3Cu2I5 thin film shows a sole emission peaking at 440 nm associated with the self-trapped exciton emission. Doping of Tl⁺ ions introduces another emission peaking at 520 nm. The scintillation efficiency of both undoped and Tl-doped Cs3Cu2I5 thin films is about one third of CsI:Tl thin film with the same size and thickness. Within the first five seconds after X-ray cutoff, afterglow signal of both the undoped and Tl-doped Cs3Cu2I5 thin films were over one order of magnitude lower than that of CsI:Tl thin film.
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High-intensity secondary beams play a vital role in today’s particle physics and materials science research and require suitable detection techniques to adjust beam characteristics to optimally match experimental conditions. To this end we have developed a quasi-non-invasive, ultra-thin, CsI(Tl) luminophore foil detector system, based on CCD-imaging. We have used this to quantify the beam characteristics of an intensity-frontier surface muon beam used for next-generation charged lepton-flavour violation (cLFV) search experiments at the Paul Scherrer Institut (PSI) and to assess the possible use for a future High-intensity Muon Beam (HiMB-project), currently under study at PSI. An overview of the production and intrinsic characteristics of such foils is given and their application in a high-intensity beam environment.
Background:
Recent advances in photon counting detection technology have led to significant research interest in X-ray imaging.
Objective:
As a tutorial level review, this paper covers a wide range of aspects related to X-ray photon counting detector characterization.
Methods:
The tutorial begins with a detailed description of the working principle and operating modes of a pixelated X-ray photon counting detector with basic architecture and detection mechanism. Currently available methods and techniques for charactering major aspects including energy response, noise floor, energy resolution, count rate performance (detector efficiency), and charge sharing effect of photon counting detectors are comprehensively reviewed. Other characterization aspects such as point spread function (PSF), line spread function (LSF), contrast transfer function (CTF), modulation transfer function (MTF), noise power spectrum (NPS), detective quantum efficiency (DQE), bias voltage, radiation damage, and polarization effect are also remarked.
Results:
A cadmium telluride (CdTe) pixelated photon counting detector is employed for part of the characterization demonstration and the results are presented.
Conclusions:
This review can serve as a tutorial for X-ray imaging researchers and investigators to understand, operate, characterize, and optimize photon counting detectors for a variety of applications.
