Centronic

APSD data set up to 100 kHz measured at the IPEN/MB-01 research reactor facility

The data presented in this paper comes from high-precision reactor noise measurements performed at the IPEN/MB-01 research reactor facility. The quantity inferred from the measured data was the automatic power spectral density (APSD) with the frequency range extended up to 100 kHz. The basic configuration is a shortened version of the IPEN/MB-01 core, consisting of a 26×24 rectangular fuel rail assembly with the control banks fully trailed. The measured excess efficiency of this formation was equal to (10 ± 3) cfm. The subcritical degree was reached by poisoning the reactor water with boric acid (H3BO3) in concentrations of 286.8 and 578.6 ppm of natural boron. The main objective of these experiments was to test subcritical formations with regular poisoning. The average temperature of the experiment was 286.8 ppm natural boron (19.82 ± 0.37) °C and the temperature of 578.6 ppm was (19.89 ± 0.09) °C. The core was powered by the 241Am-Be (∼1.0 Ci) starting source from the facility placed in the inverter. The APSD (in counting units 2/Hz) was obtained using the IPEN/MB-01 Correlator. The basic measured data originates from the pulses of two Centronic 3He detectors placed in the region of the inverter.

Rhenium-188 standardization and determination of titration factors for radionuclide titrators and secondary standards.

The use of rhenium-188 has increased in many therapeutic applications in nuclear medicine in recent years due to its preferred properties such as spray pattern, cost-effective availability, and ease of chemistry. Two independent measurement setups were used to standardize the radioactive 188 solution. The modus operandi of the standardization was the 4πβ matching technique in which beta was detected by proportional liquid scintillation counting and gamma was detected using NaI(Tl) detectors. The secondary standard, Centronic IG12, type 20A high pressure ionization chamber, was calibrated with 188Re standard solution and the sensitivity parameter (pA MBq-1) was determined. To improve the accuracy of commercial radionuclide calibration and ensure that patients receive the optimal dose of these radioactive drugs, the Capintec CRC-15β radionuclide calibrator calibration number was also validated. This article presents the standardization of the 188Re radioactive solution by primary methods and the calibration of the standard BARC secondary ionization chamber system and the Capintec CRC-15β radionuclide calibrator.

Absolute uniformity of 57Co and analysis of the results obtained in two international comparisons.

The absolute uniformity of Co-57 was given by the method of the 4π possibilities (PC), in an efficiency extrapolation variant. An improved original method based on the use of an equivalent decomposition scheme was implemented; In addition to improving the efficiency, a decreasing slope of the induction was obtained, which reduces the uncertainty of the extrapolation. The results obtained in the co-comparison are presented in CCRI(II)-S6.Co-57 and in the main comparison code BIPM.RI(II)-K1.Co-57. This method makes it possible to simplify the correction process for 56Co and 58Co impurities, which greatly affects the measurements in the CENTRONIC-type ionization chamber. An example of the processing of this mixture will be presented, in which the effect of impurities on the results was analyzed.

Linear examination of the ionization chamber by half-life measurements of 99 mTc.

The half-life of 99 mTc was measured at the JRC using an “IC1” ionization chamber (Centronic type IG12). The result, T1/2 (99 mTc) = 6.00660 (18) h, agrees well with data from the literature. An experiment was performed on the default settings of IC1 with the ionization current embedded in an air capacitor and read as a rise in voltage over time. This ensured excellent linearity and accuracy throughout the dynamic range, but the maximum current was limited to 2 nA. In the second test, the current was read directly with a Keithley 6517 A electrometer. Application of correction factors to the electrometer’s autorange demonstrated acceptable linearity for 12 half-lives starting at 20 nA. Automatic scaling and correlation with the current reading increase the propagation factors for regular and random errors. Discrete decay curve fitting at 6-h intervals leads to the same half-life value of 99 mTc within 0.04% standard deviation (0.0025 h) over an activity spanning at least 10 half-lives ( 3 orders of magnitude).

Measure (124) I.

The article describes the measurements made in IFIN-HH in relation to the creation of a Roman Standard (124) I, consisting of: the absolute uniformity of the solution applying the 4πβ (PC) matching method; Calibrate the CENTRONIC IG12/20A ionization chamber with a uniform solution and compare it to a calculated efficiency; γ measurement of radioactive spectrometer activity and determination of impurity levels; Compare the results of the three methods.

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Standardization of ¹⁸F and its use to secure the Roman PET metrological tracer series.

This document presents the work done at IFIN-HH and user sites, with the aim of creating (18) Romanian FDG PET trace chains. It summarizes the operations: (1) the absolute uniformity of solving (18)F, by the 4πβ (PC) matching method; (ii) Control of gamma-ray impurity content and activity measurement with a gamma-ray spectrometer; (iii) half-life measurement for the detection of some short/long-lived positron emitter impurities; (iv) calibration of the CENTRONIC IG12/20A ionization chamber; (5) Calibration of commercial radionuclide calibrators.

Standardization of 64Cu and 68Ga by the 4π(PC)β-chance method and titration in an ionization chamber.

The article deals with the application of the β 4π (PC) coincidence method to join the radionuclides (64)Cu and (68)Ga. General random equations written. Two types of extrapolation are described and used for the measurement: coincidence of positron annihilation and calculation of all emitted radiation; Both methods are compared in terms of results, advantages and disadvantages. Content bug fixes applied. Standard solutions were used to calibrate the CENTRONIC IG12/20A ionization chamber and to determine the intensity of gamma ray emission.

The half-life measurement is 124Sb.

The half-life of (124)Sb was determined experimentally by following the decay of a radioactive solution source in a Centronic IG12 ionization chamber. Thousands of measurements were made over a period of 358 days, which is approximately six half-lives. However, data analysis was limited to the first 221 days to reduce the prevailing element of uncertainty associated with the hypothetical probability of a systematic error in background subtraction. The resulting value for the half-life of (124)Sb, 60.212 (11) days, is found to be in good agreement with published values, but has a smaller uncertainty. The main uncertainties relate to potential methodological errors in background correction, long-term changes in source detector geometry, and medium- and long-term instability of the instrument. Additional measurements were made using a high purity germanium reagent to confirm the above value.

Field calibration studies of ionization chambers in high-energy mixed radiation fields

Monitoring ambient doses at workplaces around high-power accelerators is a challenging task due to the complexity of the mixed scattered radiation fields encountered. At CERN, the Centronics IG5 high-pressure ionization chambers are primarily used to monitor radiation exposure in mixed fields. The monitors are calibrated to the operating quantity equivalent to ambient dose H*(10) using photon and neutron fields generated by a standard source. However, the relationship between the ionization chamber reading and the equivalent ambient dose in a mixed field of high-energy radiation can only be assessed if the spectral response of each component and the composition of the field are known. Therefore, extensive studies were carried out at the CERN-EU High-Energy Reference Field Facility, where the spectroscopic spectra of each type of particle were evaluated using Monte Carlo simulations. In addition, the studies were conducted in an accessible controlled radiation region near the loss point of CERN’s synchrotron proton beam. Comparison of measurements and calculations showed reasonable agreement for most exposure conditions. The results indicate that conventionally calibrated ionization chambers can give a satisfactory response in terms of equivalent ambient dose in stray radiation fields in high-energy accelerators in many cases. These studies are a step towards establishing a “field calibration” method for radiation shielding instruments in which Monte Carlo simulations will be used to establish a valid correlation between the response of selected detectors to a radiation field of certain high energy.

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