Radiation Measurements最新文献_第5页

Preparation and characterization of Ce3+-Doped oxyfluoride glass for X-ray scintillation and imaging applications 用于x射线闪烁和成像应用的Ce3+掺杂氟氧玻璃的制备和表征

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-12-10 DOI: 10.1016/j.radmeas.2025.107589

Prapon Lertloypanyachai , Tharadol Donjewphrai , Adisak Honok , Weerapong Chewpraditkul , Danping Chen , Piyachat Meejitpaisan , Anon Angnanon , Wuttichai Chaiphaksa , Supakit Yonphan , Jakrapong Kaewkhao

CeF₃-doped oxyfluoride scintillating glasses with the composition 50SiO₂ – 20Al₂O₃ – 10BaF₂ – 10Gd₂O₃ – 10Li₂O (SABGL) were synthesized via the melt-quenching method under a carbon-reducing environment to stabilize Ce³⁺. The optical absorption spectra confirmed the characteristic 4f → 5d transitions of Ce³⁺ and a slight red shift associated with structural modifications at higher CeF₃ contents. Photoluminescence (PL) measurements revealed strong blue emission centered at ∼438 nm, increasing monotonically with CeF₃ concentration up to 1.5 wt%. Excitation spectra showed distinct bands from both Ce³⁺ and Gd³⁺, confirming efficient Gd³⁺ → Ce³⁺ energy transfer. Time-resolved PL decay exhibited tri-exponential behavior, indicating multiple Ce³⁺ environments typical of an amorphous glass host, with the fastest component reflecting efficient radiative relaxation. Under X-ray excitation, all samples produced clear blue radioluminescence, and X-ray imaging of an IC chip demonstrated spatial resolutions of 11.0–11.8 LP/mm, comparable to commercial BGO. Radiation-shielding parameters calculated using WinXCom showed high mass attenuation coefficients and elevated effective atomic numbers (Z_eff ≈ 32–36 at low energies), attributed to the incorporation of Ba, Gd, and Ce. Compared with a Cs₂O-Fe₂O₃-P₂O₅ reference glass, the SABGL system exhibited superior attenuation below ∼0.07 MeV, confirming its suitability for low-energy photon detection and shielding. Overall, the combined scintillation performance, high spatial resolution, and favorable photon-interaction properties demonstrate that CeF₃-doped SABGL glasses, particularly the 1.5 wt% composition is promising, scalable candidates for low-energy X-ray imaging and radiation-shielding applications.

为了稳定Ce3+，在碳还原环境下，采用熔淬法合成了50SiO2 - 20Al2O3 - 10BaF2 - 10Gd2O3 - 10Li2O （SABGL）的cef3掺杂氟氧闪烁玻璃。光学吸收光谱证实了Ce3+的4f→5d跃迁特征，并且在较高的CeF3含量下，结构修饰导致了轻微的红移。光致发光（PL）测量显示，中心为~ 438 nm的强蓝色发射，随着CeF3浓度的增加单调增加，直至1.5 wt%。激发光谱显示Ce3+和Gd3+的不同波段，证实了Gd3+→Ce3+的高效能量转移。时间分辨PL衰变表现出三指数行为，表明非晶玻璃主体的多种Ce3+环境，其中最快的组分反映了有效的辐射弛豫。在x射线激发下，所有样品都产生了清晰的蓝色放射发光，IC芯片的x射线成像显示空间分辨率为11.0-11.8 LP/mm，与商用BGO相当。使用WinXCom计算的辐射屏蔽参数显示，由于Ba、Gd和Ce的掺入，质量衰减系数高，有效原子序数高（低能时Zeff≈32-36）。与cs20 - fe2o3 - p2o5基准玻璃相比，SABGL系统在~ 0.07 MeV以下表现出优越的衰减，证实了其低能光子探测和屏蔽的适用性。总的来说，综合闪烁性能、高空间分辨率和良好的光子相互作用特性表明，掺cef3的SABGL玻璃，特别是1.5 wt%的成分，是低能x射线成像和辐射屏蔽应用的有前途的、可扩展的候选材料。

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引用次数: 0

Geant4 model to estimate the dead layer thickness of the HPGe detector 利用Geant4模型估计HPGe探测器的死层厚度

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-12-09 DOI: 10.1016/j.radmeas.2025.107585

Kafa Al-Khasawneh, Yasser Alsenjlawi, Hadeel Abu-Hejleh, Muflih Alkarazneh

A simulation model of a high-purity germanium (HPGe) detector was developed. The detector's parameters were built, and the dead layer thickness was modified according to the result of the measurements of full peak detection efficiency to reach an agreement of better than 5 %. The validation of the Geant4 model was performed using both a point-like source and an extended volumetric source. The validation process shows that the developed Geant4 model is valid for full peak detection efficiency and for performing any additional geometrical and coincidence corrections.

建立了高纯锗（HPGe）探测器的仿真模型。建立了探测器的参数，并根据全峰检测效率的测量结果对死层厚度进行了修正，达到了优于5%的一致性。使用点状源和扩展的体积源对Geant4模型进行验证。验证过程表明，开发的Geant4模型对于峰值检测效率和执行任何额外的几何和符合校正是有效的。

引用次数: 0

TL/OSL emission spectrometry of alumina substrates of electronic components in mobile phones: potential of the red TL emission for retrospective dosimetry 手机电子元件氧化铝衬底的TL/OSL发射光谱法：回溯剂量测定的红色TL发射电位

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-12-08 DOI: 10.1016/j.radmeas.2025.107588

Clemens Woda , Michael Discher

Emergency dosimetry using mobile phone components has become an increasingly interesting field for post-accident dose assessment. This study investigates the TL and OSL emission properties of alumina substrates from resistors and inductors found in mobile phone circuit boards, with a focus on the dosimetric potential of the red Cr³⁺-related TL emission. Spectral measurements reveal three primary emission bands around 330 nm and 410 nm, attributable to F⁺ and F centers respectively, and a dominant emission at 695 nm, characteristic of Cr³⁺. In TL, the Cr³⁺ emission clearly dominates, particularly in resistors, with intensity exceeding that of the blue/UV emissions by up to two orders of magnitude. The red TL signal exhibits a linear dose response over a wide range (from mGy to >10 Gy), low intrinsic background, and fading characteristics consistent with anomalous fading (∼20.7 %/decade). Dose recovery experiments immediately after irradiation confirm accuracy within 7 %, a minor dose overestimation caused by minor desensitization. The red TL signal is optically bleachable, similar to its blue/UV counterpart. Irradiation trials with intact smartphones demonstrated that the red TL method delivers dose estimates within 25 % of the reference dose, comparable to established methods using display glass or OSL on resistors. Importantly, dose estimation using only a single resistor achieved similar sensitivity to protocols requiring ten components in the blue/UV range. These results highlight the potential of red TL for accurate, sensitive, and minimally invasive retrospective dosimetry. The method offers distinct advantages in scenarios where only few components are available and enables the prospect of non-destructive measurements.

使用移动电话组件进行应急剂量测定已成为事故后剂量评估的一个日益有趣的领域。本研究研究了手机电路板中电阻器和电感的氧化铝基板的TL和OSL发射特性，重点研究了红色Cr3+相关TL发射的剂量学电位。光谱测量显示，在330 nm和410 nm附近有三个主要的发射波段，分别属于F+和F中心，在695 nm处有一个主要的发射波段，这是Cr3+的特征。在TL中，Cr3+发射明显占主导地位，特别是在电阻器中，其强度超过蓝/紫外发射高达两个数量级。红色TL信号在较宽的范围内（从mGy到>；10 Gy）表现出线性剂量响应，低本征本征，以及与异常衰减（~ 20.7% / 10年）一致的衰减特性。辐照后立即进行剂量恢复实验，证实准确度在7%以内，这是由于轻微脱敏引起的轻微剂量高估。红色TL信号是光学可漂白的，类似于它的蓝色/紫外线对应物。用完整的智能手机进行的辐射试验表明，红色TL方法提供的剂量估计在参考剂量的25%以内，与使用显示玻璃或OSL电阻的现有方法相当。重要的是，仅使用单个电阻器的剂量估计与在蓝色/紫外线范围内需要十个组分的方案具有相似的灵敏度。这些结果突出了红色TL在准确、敏感和微创回顾性剂量测定方面的潜力。该方法在只有少数组件可用的情况下具有明显的优势，并且可以进行非破坏性测量。

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引用次数: 0

Experimental approach of internal dose map visualization during helical CT examinations: importance of X-ray incident direction analysis and central internal dose estimation 螺旋CT检查内剂量图可视化的实验方法：x射线入射方向分析和中心内剂量估计的重要性

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-12-05 DOI: 10.1016/j.radmeas.2025.107586

Hiroaki Hayashi , Kazuki Takegami , Rina Nishigami , Daiki Kobayashi , Sota Goto , Takashi Asahara , Natsumi Kimoto , Masaki Takemitsu , Rin Ishii , Shinichi Morimoto , Motochika Maki

During computed tomography (CT) examination, radiation exposures should be appropriately managed taking into considering the effects of bowtie filter, the heel effect and over-beaming effect. Furthermore, the analysis of an X-ray incident direction is important. The purpose of this study is to develop a procedure to obtain two-dimensional (2D) internal dose distributions based on actual measurements of surface dose distribution and central internal dose data. Experiments were conducted using a clinical CT scanner and four cylindrical polyacetal resin (POM) phantoms having diameters of 15–30 cm. The entrance surface doses and the central internal dose were measured by placing the optically stimulated luminescence (OSL) dosimeters on the surface and inner part of the phantom, respectively, during helical CT scans. The X-ray incident direction at the slice containing the dosimeter was estimated based on the noise distribution analysis of the CT image. Then, circumferential surface dose distributions were determined as a function of the X-ray incident direction. Based on these experimental data, we succeeded in visualizing the 2D dose distributions. The obtained dose distribution was inhomogeneous, clearly reflecting the influence of factors such as the heel effect. The uncertainty due to our methodology was estimated to be from 4.3 % to 7.4 %. Our methodology needs central internal dose data, and the absence of this data introduced additional systematic uncertainties of +6.9 % to −11.4 %. In conclusion, correcting for the effect of the X-ray incident directions for entrance surface dose and adding the central inner dose data can improve the reliability of the internal dose distribution.

在计算机断层扫描（CT）检查中，应适当地管理辐射暴露，考虑领结滤光片、足跟效应和过束效应的影响。此外，对x射线入射方向的分析也很重要。本研究的目的是根据实际测量的表面剂量分布和中心内剂量数据，建立一种获得二维（2D）内剂量分布的程序。实验使用临床CT扫描仪和4个直径为15-30 cm的圆柱形聚缩醛树脂（POM）模型进行。在螺旋CT扫描过程中，分别将光激发发光（OSL）剂量计放置在幻体的表面和内部来测量入口表面剂量和中心内部剂量。基于CT图像的噪声分布分析，估计了含有剂量计的切片处的x射线入射方向。然后，确定了x射线入射方向的周向表面剂量分布。基于这些实验数据，我们成功地实现了二维剂量分布的可视化。所得剂量分布不均匀，明显反映了足跟效应等因素的影响。由于我们的方法导致的不确定性估计在4.3%到7.4%之间。我们的方法需要中心内剂量数据，缺少这些数据会导致额外的系统不确定度为+ 6.9%至- 11.4%。综上所述，修正x射线入射方向对入口表面剂量的影响，加入中心内剂量数据，可以提高内剂量分布的可靠性。

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引用次数: 0

Energy spectra from ionising radiation in the troposphere and stratosphere measured with a super-miniaturised scintillator detector 用超小型闪烁体探测器测量对流层和平流层电离辐射的能谱

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-12-03 DOI: 10.1016/j.radmeas.2025.107581

Karen L. Aplin , Justin D. Tabbett , Isobel M.P. Houghton

Motivated by the need to measure and understand the role of energetic particles in atmospheric processes, a super-miniaturised (40 g) CsI(Tl) scintillator (“microscintillator”) coupled to a PiN photodiode has been developed and tested in the atmosphere up to an altitude of 32 km. Specifically, a microscintillator and Geiger counters were flown with a meteorological radiosonde in July 2024. Separately, a hand-held microscintillator was carried on transatlantic passenger flights in March 2025. These deployments all occurred during calm space weather conditions, meaning that particles created by the galactic cosmic ray (GCR) background could be measured within the energy range of the instrument, 0.02–10 MeV. Geiger and microscintillator count rates from the balloon were well-correlated, with maximum count rates at ∼21 km, consistent with previous work. The spectral peak was centred on 1–2 MeV with an exponential decay coefficient of ∼0.5 MeV, consistent with the background GCR gamma spectrum. Energy spectra from the balloon and passenger flight at 10–12 km were consistent, with minor differences explained by lower-energy gammas and electrons not penetrating the plane's fuselage. Spectral lines from gammas created by GCR-neutron interactions with the atmosphere were detected in airborne data and were absent from ground-based data. These technology demonstrator flights provide background reference GCR ionising radiation spectra for comparison with more disturbed space weather conditions, where additional particles would be expected. Detection of gamma rays from GCR neutrons offers a way to directly calibrate neutrons measured at Earth's surface to ionising radiation in the atmosphere.

由于需要测量和了解高能粒子在大气过程中的作用，一种超小型（40克）CsI（Tl）闪烁体（“微闪烁体”）与PiN光电二极管耦合，已经开发出来，并在高达32公里的大气中进行了测试。具体来说，2024年7月，一个微闪烁体和盖革计数器与一个气象无线电探空仪一起飞行。另外，2025年3月，一种手持式微闪烁器被用于跨大西洋客运航班。这些部署都发生在平静的太空天气条件下，这意味着银河宇宙射线（GCR）背景产生的粒子可以在仪器的能量范围内测量，0.02-10兆电子伏特。来自气球的盖革和微闪烁计数率具有良好的相关性，最大计数率在~ 21公里处，与先前的工作一致。光谱峰集中在1-2 MeV，指数衰减系数为~ 0.5 MeV，与背景GCR伽马谱一致。气球和乘客在10-12公里处飞行的能谱是一致的，有微小的差异可以解释为低能伽马和电子没有穿透飞机的机身。由gcr -中子与大气相互作用产生的伽马谱线在机载数据中被探测到，而在地面数据中则没有。这些技术演示飞行提供了背景参考GCR电离辐射光谱，以便与更受干扰的空间天气条件进行比较，在这些条件下预计会有额外的粒子。探测GCR中子的伽马射线提供了一种方法，可以直接校准在地球表面测量到的中子与大气中的电离辐射。

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引用次数: 0

Enhanced bulk-etch-rate of gamma irradiated PADC detector expressed by the radiation chemical yield of hydroxyl group 用羟基的辐射化学产率表示γ辐照PADC探测器的增强体刻蚀率

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-12-03 DOI: 10.1016/j.radmeas.2025.107584

Reo Yamada , Atsushi Kimoto , Hayato Seiichi , Shunto Sadamitsu , Daisuke Kohinata , Masato Kanasaki , Tamon Kusumoto , Hisashi Kitamura , Satoshi Kodaira , Sachiko Tojo , Tomoya Yamauchi

Enhanced bulk-etch-rate of PADC (polyallyl diglycol carbonate) detectors exposed to gamma rays has been found to be described well as an exponential function of the product of the radiation chemical yield of hydroxyl group (G_OH) and the adsorbed dose (D) at different dose-rates between 0.41 and 8.14 Gy/s. The examined absorbed doses were ranging from 30 to 100 kGy, comparable with the local dose in proton tracks. By matching the bulk-etch-rates and the G_OH values obtained under identical conditions on dose-rate, the following equation was derived for the relative bulk-etch-rate, V_irra/V_b = exp(y･G_OH･D), where, V_irra and V_b denote the bulk-etch-rates after and before gamma irradiations, respectively, and y is an experimentally obtained constant in a unit of kg/mol, with a value of y = 5.98. In this relation, significant dose-rate dependence is explained as the dose-rate dependence of the G_OH value. This means that the radiation damage that increases the bulk-etch-rate is the hydroxyl group itself, and y appears as a constant specific to PADC which relates the damage to bulk-etch-rate. Here, y is termed the “etching coefficient ".

在0.41和8.14 Gy/s之间的不同剂量率下，暴露于伽马射线下的PADC（聚烯丙基碳酸二甘醇）探测器的增强体腐蚀速率可以很好地描述为羟基（GOH）的辐射化学产率和吸附剂量(D)的乘积的指数函数。所检查的吸收剂量范围为30至100千戈瑞，与质子轨道的局部剂量相当。将相同剂量率条件下得到的体蚀率和GOH值进行匹配，得到体蚀率的相对方程Virra/Vb = exp（y弧弧弧弧弧度），其中，Virra和Vb分别表示辐照前后的体蚀率，y为实验得到的常数，单位为kg/mol， y = 5.98。在这个关系中，显著的剂量率依赖性被解释为GOH值的剂量率依赖性。这意味着增加体蚀速率的辐射损伤是羟基本身，y表现为PADC特有的常数，这与体蚀速率的损伤有关。这里，y被称为“蚀刻系数”。

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引用次数: 0

Development of an omnidirectional Compton camera with enhanced energy resolution for radioactive source localization 全向康普顿相机的研制，增强了辐射源定位的能量分辨率

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-12-03 DOI: 10.1016/j.radmeas.2025.107583

Xinyu Yang , Jian Yang , Guoqiang Zeng , Haowen Deng , Chengshuai Tian , Chuanhao Hu

For radioactive source localization, traditional Compton cameras are limited by the imaging field-of-view (FOV) and low detection efficiency, resulting in slow response in complex environments. To address the limitations in the azimuthal sensitivity of conventional dual-layer scintillator detectors and the sensitive volume of semiconductor detectors, this study proposes an omnidirectional Compton camera based on four-sided scintillator detectors with a square ring-shaped structure. This imaging system features omnidirectional sensitivity with a continuous 360° azimuthal response, significantly enhancing detection efficiency by minimizing the escape of scattered photons. The smallest imaging unit utilizes an independent CsI(Tl) crystal coupled with a single SiPM, which reduces light propagation loss and improves light collection efficiency to enhance energy resolution. To simplify the electronic systems, a serial readout circuit is employed to reduce the readout channels. The experimental results demonstrate that the total energy resolution for the ¹³⁷Cs source was 6.2 % (FWHM) after calibrating the position and energy. Using the maximum likelihood expectation maximization algorithm for image reconstruction, the imaging system achieves accurate localization of radioactive sources with an angular resolution of 12° and clearly distinguishes the position of two radioactive sources.

对于放射源定位，传统康普顿相机受成像视场（FOV）和检测效率低等限制，在复杂环境下响应缓慢。针对传统双层闪烁体探测器方位灵敏度和半导体探测器灵敏体积的局限性，本研究提出了一种基于四边闪烁体探测器的方形环形结构全向康普顿相机。该成像系统具有全向灵敏度，具有连续的360°方位响应，通过最大限度地减少散射光子的逃逸，显著提高了探测效率。最小的成像单元利用独立的CsI（Tl）晶体与单个SiPM相结合，减少了光传播损失，提高了光收集效率，从而提高了能量分辨率。为了简化电子系统，采用串行读出电路来减少读出通道。实验结果表明，经位置和能量标定后，137Cs源的总能量分辨率为6.2% （FWHM）。成像系统采用最大似然期望最大化算法进行图像重建，实现了放射源的精确定位，角度分辨率达到12°，清晰区分了两个放射源的位置。

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引用次数: 0

Use of gamma-ray spectroscopy in thickness gauging of a complex-shaped lead shield 伽玛射线光谱在复杂形状铅屏蔽厚度测量中的应用

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-12-02 DOI: 10.1016/j.radmeas.2025.107582

Joseph Graham , Brian Durtschi , Ashish Avachat , Seth Kilby

Methods for measuring the thickness of lead shielding based on ⁶⁰Co gamma-ray spectroscopy are presented. In applications where a shield’s thickness is multiple mean free paths and the shield has a complex shape (i.e. cannot be approximated as a simple solid such as a slab, sphere, semi-infinite medium, etc.), the necessary buildup factors are not available. Thus, determination of shield thickness by means of the Beer–Lambert law requires separating the counts from uncollided photons from the scattered photon contribution. It is demonstrated how the 1332 keV gamma ray of ⁶⁰Co can be used to precisely quantify lead thicknesses up to at least

\sim

280 mm. Use of the ratio of 1173 keV to 1332 keV photopeak areas to determine thickness is also discussed.

提出了基于60Co伽马能谱法测量铅屏蔽层厚度的方法。在屏蔽厚度为多个平均自由路径且屏蔽具有复杂形状的应用中（即不能近似为简单的固体，如板，球体，半无限介质等），不可用必要的累积因子。因此，通过比尔-朗伯定律确定屏蔽厚度需要将未碰撞光子的计数与散射光子的贡献分开。演示了60Co的1332 keV伽马射线如何用于精确量化铅的厚度，厚度至少可达~ 280 mm。利用1173 keV与1332 keV光峰面积的比值来确定厚度也进行了讨论。

引用次数: 0

Wavelength-dependent cross section for optically stimulated luminescence in Y2SiO5:Ce Y2SiO5:Ce光激发发光的波长相关截面

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-11-28 DOI: 10.1016/j.radmeas.2025.107566

Jacob C. Warming, Peter Balling, Rosana M. Turtos

Long-lived defect states in large-band-gap materials can potentially store energy from ionising radiation allowing the materials to be used as dosimeters. The population in many of these dosimetric traps can be read out with optically stimulated luminescence (OSL). OSL is associated with a cross section for the excitation probability, and the wavelength dependence of the cross section provides insight into the physical characteristics of the traps and allows for an optimised readout of OSL-dosimeters.

This paper suggests a novel approach to measuring the optical cross section using a pulsed tunable laser. A model of the evolution of the trap population is used to analyse data taken pulse-by-pulse to determine the cross sections in Y

_{2}

SiO₅:Ce. The cross sections are compared to theoretical models in order to determine the trap depth and phonon contribution. The wavelength-dependent cross section increases monotonically as the wavelength decreases, varying by more than two orders of magnitude from

1 0^{- 24}

at the longest wavelengths (800 nm) to more than

1 0^{- 22}

m

^{2}

in the green and blue part of the spectrum. Depending on the theoretical model used, the main trap depth is within the range 2.1–2.6 eV with a characteristic value of 2.3 eV, aligning with published results. Additionally, a notable phonon contribution is found with a magnitude that is consistent with previously reported phonon energies.

大带隙材料中的长寿命缺陷态可以潜在地储存电离辐射产生的能量，从而使材料可用作剂量计。在许多这些剂量测定陷阱的人口可以读出光激发发光（OSL）。OSL与激发概率的横截面相关联，横截面的波长依赖性提供了对陷阱物理特性的深入了解，并允许优化OSL剂量计的读数。本文提出了一种利用脉冲可调谐激光器测量光学截面的新方法。圈闭种群的演化模型用于分析逐脉冲采集的数据，以确定Y2SiO5:Ce的横截面。为了确定陷阱深度和声子贡献，将截面与理论模型进行了比较。波长相关的截面随着波长的减小而单调增加，变化超过两个数量级，从最长波长（800 nm）的10−24到光谱的绿色和蓝色部分的10−22 m2以上。根据所使用的理论模型，主要陷阱深度在2.1-2.6 eV范围内，特征值为2.3 eV，与已发表的结果一致。此外，一个显著的声子贡献被发现，其大小与先前报道的声子能量一致。

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引用次数: 0

RQR beam qualities measurement with the Timepix4 detector Timepix4探测器的RQR波束质量测量

IF 2.2 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements

Pub Date : 2025-11-28 DOI: 10.1016/j.radmeas.2025.107570

T. Genetay , L. Tlustos , M. Campbell , F. Bochud , P. Carbonez , J. Damet

This work presents, to the best of the authors’ knowledge, the first attempt at reconstructing X-ray spectra with a hybrid pixel detector for radiation protection applications in the scattered field around fluoroscopy devices. The performance of the Timepix4 detector was evaluated under reference conditions using RQR beam qualities. A dedicated methodology was developed to correct for detection efficiency, explicitly accounting for contributions from Compton scattering and the photoelectric effect. Accuracy was assessed through Monte Carlo simulations and comparisons with published RQR reference spectra. In addition, particle fluence measurements obtained with Timepix4 were validated against values derived from kerma factors and ionisation chamber measurements performed in a calibration laboratory. The results show excellent agreement between reconstructed and reference spectra up to

70 keV

, with residuals below 1.7% and relative photon fluence shifts within 5%. At higher energies, discrepancies increase due to the low detection efficiency of the silicon sensor, requiring large correction factors and leading to greater statistical fluctuations. Nevertheless, the system demonstrated acceptable performance up to

120 keV

, with fluence shifts remaining below 16%. Linearity was confirmed across all beam qualities and intensities investigated, consistent with previous studies on earlier Timepix ASIC generations. Overall, these findings demonstrate that Timepix4 can provide reliable spectral and fluence measurements in reference X-ray beams, offering valuable information for radiation protection studies in scattered fields where conventional detectors are of limited use. Future improvements in readout bandwidth and spectral deconvolution methods are expected to extend its applicability to higher energies and clinical environments.

据作者所知，这项工作首次尝试用混合像素探测器重建x射线光谱，用于透视装置周围散射场的辐射防护应用。在参考条件下，利用RQR波束质量评价Timepix4探测器的性能。开发了一种专门的方法来纠正检测效率，明确地考虑了康普顿散射和光电效应的贡献。通过蒙特卡罗模拟和与已发表的RQR参考光谱的比较来评估准确性。此外，用Timepix4获得的粒子通量测量值与在校准实验室进行的kerma因子和电离室测量得出的值进行了验证。结果表明，在70keV范围内，重建光谱与参考光谱具有良好的一致性，残差在1.7%以下，相对光子通量漂移在5%以内。在较高的能量下，由于硅传感器的检测效率较低，差异增大，需要较大的校正因子，导致更大的统计波动。尽管如此，该系统在高达120keV的电压下表现出了可接受的性能，影响位移保持在16%以下。所有被调查的光束质量和强度都证实了线性，这与之前对Timepix ASIC的早期研究一致。总的来说，这些发现表明Timepix4可以在参考x射线光束中提供可靠的光谱和通量测量，为传统探测器用途有限的散射场辐射防护研究提供有价值的信息。未来在读出带宽和频谱反卷积方法方面的改进有望将其应用于更高能量和临床环境。

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引用次数: 0