Classification of radioxenon spectra with deep learning algorithm.

In this study, we propose for the first time a model of classification for Beta-Gamma coincidence radioxenon spectra using a deep learning approach through the convolution neural network (CNN) technique. We utilize the entire spectrum of actual data from a noble gas system in Charlottesville (USX75 station) between 2012 and 2019. This study shows that the deep learning categorization can be done as an important pre-screening method without directly involving critical limits and abnormal thresholds. Our results demonstrate that the proposed approach of combining nuclear engineering and deep learning is a promising tool for assisting experts in accelerating and optimizing the review process of clean background and CTBT-relevant samples with high classification average accuracies of 92% and 98%, respectively.

The automatic frequency control based on artificial intelligence for compact particle accelerator.

In this work, an advantage actor critic (A2C) based intelligent automatic frequency control (AFC) system was developed for X-band linear accelerator (LINAC). A2C is one type of reinforcement learning, which indicates how software agents should perform actions in an environment. In this paper, the A2C based AFC algorithm and its environment design, simulation result, and controller hardware and software processes are described. The objective of our design is to match LINAC and magnetron frequency, and it is implemented via reward shaping using comparison with the reflected power in the adjacent time. The simulation with the A2C algorithm was implemented in two modes, namely, periodic and White Gaussian Noise (WGN) waves, for analysis with temperature and random disturbance, respectively. In order to create artificial disturbance in the experiment, the magnetron shaft was shifted randomly every 0.5 s by using WGN with 18° angle of the step motor. The standard deviation of the reflected power was 5.63 kW, and the average power was 130.9 kW. To obtain maximum reward at the beginning of the A2C training, the adjacent frequency is needed. The measured average reflected power and standard deviation were 122.8 kW and 1.75 kW, respectively, after 2000 iterations. The results show that the reflected power and standard deviation of the AFC with A2C were lower compared to open-loop with artificial disturbance. The RF station of a medical X-band LINAC was used as the test bench, and the performance was confirmed by the results of an experiment conducted at Sungkyunkwan University in Korea.

Development of a disposable kit with fully automatic self-shielding reactor for [18F]FDG synthesis.

A self-shielding device for the synthesis of radiopharmaceuticals was developed and fabricated in this study. Radiation exposure was minimized by the self-shielding of the kit, installation of the disposable kit in the auxiliary chamber while in a shielded state, and discharge of the kit into a radioactive waste container upon completion of the synthesis process. The developed self-shielding synthesis kit was tested by synthesizing 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) in order to verify its performance.

Development of an 83.2 MHz, 3.2 kW solid-state RF amplifier using Wilkinson power divider and combiner for a 10 MeV cyclotron.

We design a stripline-type Wilkinson power divider and combiner for a 3.2 kW solid-state radio frequency (RF) amplifier module and optimize this setup. A Teflon-based printed circuit board is used in the power combiner to transmit high RF power efficiently in the limited space. The reflection coefficient (S11) and insertion loss (S21) related to impedance matching are characterized to determine the optimization process. The resulting two-way divider reflection coefficient and insertion loss were -48.00 dB and -3.22 dB, respectively. The two-way power combiner reflection coefficient and insertion loss were -20 dB and -3.3 dB, respectively. Moreover, the 3.2 kW solid-state RF power test results demonstrate that the proposed power divider and combiner exhibit a maximum efficiency value of 71.3% (combiner loss 5%) at 48 V supply voltage.

Performance optimization of H(-) multicusp ion source for KIRAMS-30 cyclotron.

KIRAMS-30 cyclotron has been developed and implemented for radio isotope production. For the purpose of producing negative hydrogen ions and low energy beam injection to the central region of KIRAMS-30, 10 mA H(-) multicusp ion source with beam kinetic energies in the 20-30 keV range and the normalized 4 rms emittance less than 1 mm mrad was installed. The optimized ion source operating condition is presented and the correlation between the extracted beam current and ion source parameters is described for the performance enhancement of the ion source.

Design and evaluation of the tandem target for a simultaneous production of [11C]CH4 and [18F]-fluoride.

The tandem target for a simultaneous production of [11C]CH4 and [(18)F]-fluoride has been designed and evaluated. A separate recovery system has been applied for a simultaneous collection of [11C]CH4 and [(18)F]-fluoride after a bombardment. The [11C]CH4 target was placed in front, and the [18F]-fluoride target was posted successively. An aluminum grid was employed between the two target cavities to improve the burst pressure of the titanium foil during an irradiation. It was demonstrated that a useful amount of [11C]CH4 and [18F]-fluoride can be produced simultaneously by this newly designed system.