Градуировка сцинтилляционного спектрометра гамма-излучений с применением метода математического моделирования

The article describes a method for calibrating a gamma ray spectrometer using a three-dimensional simulation program for the transfer and registration of ionizing radiation. In the example of calibration of plane source counters (filter AFA-RMP20), this method allows one to determine the activity by using spectrometric equipment based on inorganic scintillation crystals. We proposed a method for parametric estimation of the identity of the calculated and experimental spectrum based on the Pearson agreement criterion. We then performed interlaboratory comparisons. The results demonstrate that the difference between measured values of the activity in the test samples of radionuclides using obtained calibration and values measured with a semiconductor based calibrated spectrometer do not exceed 20%.В статье описан метод градуировки спектрометра гамма-излучений с применением программы имитационного трехмерного моделирования процессов переноса и регистрации ионизирующих излучений. Метод на примере градуировки, проведенной на счетном образце в виде плоского источника (фильтр АФА-РМП20), предоставляет возможность определения активности с применением спектрометрического оборудования на основе неорганических сцинтилляционных кристаллов. Предложен способ параметрической оценки идентичности расчетного и экспериментального спектра на основе критерия согласия Пирсона. Проведены сличительные испытания. Представлены результаты апробации предложенного метода, показывающие, что различие результатов измерений активности исследуемых образцов радионуклидов на основе полученной градуировки по сравнению с результатами измерений активности, выполненных с помощью калиброванного спектрометра на базе полупроводникового детектора, не превышает 20%

FindFoci: a focus detection algorithm with automated parameter training that closely matches human assignments, reduces human inconsistencies and increases speed of analysis

Accurate and reproducible quantification of the accumulation of proteins into foci in cells is essential for data interpretation and for biological inferences. To improve reproducibility, much emphasis has been placed on the preparation of samples, but less attention has been given to reporting and standardizing the quantification of foci. The current standard to quantitate foci in open-source software is to manually determine a range of parameters based on the outcome of one or a few representative images and then apply the parameter combination to the analysis of a larger dataset. Here, we demonstrate the power and utility of using machine learning to train a new algorithm (FindFoci) to determine optimal parameters. FindFoci closely matches human assignments and allows rapid automated exploration of parameter space. Thus, individuals can train the algorithm to mirror their own assignments and then automate focus counting using the same parameters across a large number of images. Using the training algorithm to match human assignments of foci, we demonstrate that applying an optimal parameter combination from a single image is not broadly applicable to analysis of other images scored by the same experimenter or by other experimenters. Our analysis thus reveals wide variation in human assignment of foci and their quantification. To overcome this, we developed training on multiple images, which reduces the inconsistency of using a single or a few images to set parameters for focus detection. FindFoci is provided as an open-source plugin for ImageJ

ПОСЛЕАВАРИЙНЫЙ КОНТРОЛЬ ВНУТРЕННЕГО ОБЛУЧЕНИЯ ПРИ РАДИАЦИОННЫХ АВАРИЯХ НА КОРАБЛЯХ И СУДАХ С ЯДЕРНЫМИ ЭНЕРГЕТИЧЕСКИМИ УСТАНОВКАМИ: ЗАДАЧИ И АППАРАТУРНО-МЕТОДИЧЕСКОЕ ОБЕСПЕЧЕНИЕ

In the case of radiation accident on a board of ships and vessels with nuclear power units, radioactive substances can be released into the environment and absorbed by the human body. The radioactive contamination is associated with a complex and rapidly disintegrating composition of radionuclides, which are products of nuclear fission and induced radioactivity. Therefore, the need for prompt post-accident control of internal exposure is justified. In the article, radiation accidents are classified in relation to ships and vessels with nuclear power units. As an example, one of the most severe accidents that occurred when nuclear fuel was transshipped on a nuclear-powered submarine in the Chazhma Bay in 1985 is considered. Methods for determining the incorporated radioactivity are described. Direct measurement of radionuclide content in a human body or an organ using human radiation spectrometers is shown to be the most accurate. The hardware-methodical support and the main measures for the postemergency individual control of the internal exposure of personnel of vessels with nuclear power plants are proposed.При чрезвычайной ситуации радиационного характера на кораблях и судах с ядерными энергетическими установками может произойти выброс радиоактивных веществ в окружающую среду и их поступление в организм человека. Радиоактивное загрязнение характеризуется сложным и быстро распадающимся во времени составом радионуклидов – продуктами ядерного деления и наведенной активности, что обосновывает необходимость оперативного послеаварийного контроля внутреннего облучения. В статье приводится классификация радиационных аварий применительно к кораблям. В качестве примера рассматривается одна из наиболее тяжелых аварий, которая произошла при перегрузке ядерного топлива на атомной подводной лодке в бухте Чажма в 1985 г. Описываются способы определения инкорпорированной активности. Показано, что наиболее точным является метод прямого измерения содержания радионуклидов в организме или органе с применением спектрометров излучений человека. Предлагается аппаратурно-методическое обеспечение и схема основных мероприятий при осуществлении послеаварийного индивидуального контроля внутреннего облучения персонала судов с ядерными энергетическими установками

INTERNAL IRRADIATION CONTROL AFTER RADIATION ACCIDENTS ON SHIPS AND VESSELS WITH NUCLEAR POWER UNITS: TASKS AND HARDWARE-METHODICAL SUPPORT

In the case of radiation accident on a board of ships and vessels with nuclear power units, radioactive substances can be released into the environment and absorbed by the human body. The radioactive contamination is associated with a complex and rapidly disintegrating composition of radionuclides, which are products of nuclear fission and induced radioactivity. Therefore, the need for prompt post-accident control of internal exposure is justified. In the article, radiation accidents are classified in relation to ships and vessels with nuclear power units. As an example, one of the most severe accidents that occurred when nuclear fuel was transshipped on a nuclear-powered submarine in the Chazhma Bay in 1985 is considered. Methods for determining the incorporated radioactivity are described. Direct measurement of radionuclide content in a human body or an organ using human radiation spectrometers is shown to be the most accurate. The hardware-methodical support and the main measures for the postemergency individual control of the internal exposure of personnel of vessels with nuclear power plants are proposed