Conceptual design of the Hybrid Ring with superconducting linac

The Hybrid Ring with a superconducting-linac injector as a highly flexible synchrotron radiation source to enable new experimental techniques and enhance many existing ones is proposed. It is designed to be operated with the coexistence of the storage (SR) bunches characterized by the performance of the storage ring, and the single-pass (SP) bunches characterized by the performance of the superconducting linac. Unique experiments can be performed by simultaneous use of the SR and SP beams, in addition to research with various experimental techniques utilizing the versatile SR beam and research in the field of ultrafast dynamics utilizing the ultrashort pulse of the SP beam. The extendability of the Hybrid Ring will allow it to be developed into a synchrotron radiation complex.

Novel LED-based radiation source and its application in diffuse reflectometry and polarization measurements

An LED sphere radiator (LED-SR) was constructed to improve the accuracy in spectral radiance factor measurements performed with the robot-based gonioreflectometer at PTB. Its properties with respect to the spectral range and coverage, the temporal stability, and the homogeneity of the radiation field are presented. Two types of matte ceramic reflection standards were used for spectral radiance factor validation measurements comparing the standardly used halogen sphere radiator (Halogen-SR) and the LED-SR. Due to its designed spectral range at the border between the visible and the UV-A spectral range, the LED-SR is well suited for many applications in diffuse reflectometry. Its use for absolute radiance factor measurements and investigations of the fluorescence properties of diffuse reflecting samples is shown. Reliable polarization-resolved measurements at wavelengths below 430 nm could be carried out with PTB’s gonioreflectometer for the first time due to the beneficial signal-to-noise ratio of the LED-SR.

ROS- and Radiation Source-Dependent Modulation of Leukocyte Adhesion to Primary Microvascular Endothelial Cells

Anti-inflammatory effects of low-dose irradiation often follow a non-linear dose–effect relationship. These characteristics were also described for the modulation of leukocyte adhesion to endothelial cells. Previous results further revealed a contribution of reactive oxygen species (ROS) and anti-oxidative factors to a reduced leukocyte adhesion. Here, we evaluated the expression of anti-oxidative enzymes and the transcription factor Nrf2 (Nuclear factor-erythroid-2-related factor 2), intracellular ROS content, and leukocyte adhesion in primary human microvascular endothelial cells (HMVEC) upon low-dose irradiation under physiological laminar shear stress or static conditions after irradiation with X-ray or Carbon (C)-ions (0–2 Gy). Laminar conditions contributed to increased mRNA expression of anti-oxidative factors and reduced ROS in HMVEC following a 0.1 Gy X-ray and 0.5 Gy C-ion exposure, corresponding to reduced leukocyte adhesion and expression of adhesion molecules. By contrast, mRNA expression of anti-oxidative markers and adhesion molecules, ROS, and leukocyte adhesion were not altered by irradiation under static conditions. In conclusion, irradiation of endothelial cells with low doses under physiological laminar conditions modulates the mRNA expression of key factors of the anti-oxidative system, the intracellular ROS contents of which contribute at least in part to leucocyte adhesion, dependent on the radiation source.

Application of Serpent Monte Carlo Code for Modeling of Non-destructive Systems Based on Backscattered X-Rays

Research of objects with unilateral access is a promising area for the development of non-destructive testing systems. To create a real system and determine its optimal parameters, it is important to conduct preliminary computer simulations. The paper is devoted to creating a model of a non-destructive system based on backscattered X-rays in the Serpent Monte Carlo code. There are no known studies of the use of Serpent software to build such models. The purpose of the study was to confirm the possibility of detecting a defect, i.e., a material of a different density than the test object, which was placed in this object. A model was created, the main components of which were the radiation source, the object under study, the defect, and the detector of backscattered radiation. Experiments were performed for several combinations of system parameters, in particular when changing the angle of illumination and the distance between the object and the detector. The energy of the radiation source used in the study was 100 keV. The test object of study was a steel plate, which contained a defect — a lead plate. Calculations were performed for six cases at illumination angles of 30 and 45 degrees (scattering angles of 120 and 135 degrees, respectively), and the distance between the object and the detector 1 and 5 cm. The detector was a plane that coincided with a NaI scintillation plate of 60 by 30 cm in size. It was conventionally divided into 1800 elements to detect the flux density of backscattered radiation. A qualitative and quantitative analysis of the results met theoretical expectations. In particular, the Compton equation was fulfilled, which states that as the cosine of the scattering angle \theta increases, the energy of scattered radiation also increases. In the case of θ = 1200, the average flux density of backscattered radiation recorded by the detector was 1.1*10-3 units per square centimeter per second, and in the case of θ = 1350, this value was 7.9*10-4. The results of the study can be used to build real non-destructive testing devices. These devices can be used in medicine, industry, and security systems. The model has some limitations. The radiation source in this model is monoenergetic, in contrast to classical X-ray systems, in which the radiation has a spectrum. Also, a defect is a plate of a large area, which is almost equal to the area of ​​the object under study. For practical use, the device must be capable to detect a defect many times smaller than the object under study, such as a void in the weld, a tumor in the human body, or smuggled substances. The model can be improved in the future.

Usulan kriteria pemulangan pasien (patient release) kedokteran nuklir di Indonesia

Nuclear medicine procedures are carried out by applying a radioactive substance to the patient’s body. Thus, the patient can be assumed to be a ‘radiation source’ and needs to follow special provisions so that his presence does not expose nearby individuals unnecessarily. Therefore, when the patient is released from the hospital, it must ensure that the patient’s radiation exposure does not expose the individuals in the vicinity. However, several related regulations have not regulated this in detail. In this paper, a study is carried out regarding the criteria considered in the release of nuclear medicine patients. The method used is a literature study. The study results recommend release criteria through two approaches based on the estimated maximum effective dose that the public may accept, namely conditional release with a calculated dose of less than or equal to 5 mSv and unconditional release with an estimated dose of less than or equal to 1 mSv. Conditional release is the release of a patient provided with post-release guidance, while unconditional release is the release of the patient without being supplied with post-release advice. Keywords: nuclear medicine, patient release, conditional release, unconditional release