Journal Sciences News
Mental Health and Physical Activity
1 August 2018
Generalized equation for the sum-peak method, accounting for random coincidences
Publication date: 1 August 2018
Source:Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 898 Author(s): T. Nemes, D. Mrdja, I. Bikit For gamma cascade emitting radionuclides, the source activity can be determined by a single spectrometer from the sum peak area. At high count rates, random coincidence corrections must be considered. Starting from the equations of the peak and total count rates that consider random summing, a new equation for measurement of the activity is deduced. The results of the new formula are verified by Monte Carlo simulations.
1 August 2018
On the accuracy of Monte Carlo based beam dynamics models for the degrader in proton therapy facilities
Publication date: 1 August 2018
Source:Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 898 Author(s): V. Rizzoglio, A. Adelmann, C. Baumgarten, D. Meer, J. Snuverink, V. Talanov In a cyclotron-based proton therapy facility, the energy changes are performed by means of a degrader of variable thickness. The interaction of the proton beam with the degrader creates energy tails and increases the beam emittance. An accurate model of the degraded beam properties is important not only to better understand the performance of a facility already in operation, but also to support the development of new proton therapy concepts. The precision of the degraded beam properties, in terms of energy spectrum and transverse phase space, is influenced by approximations in the model of the particle–matter interaction. In this work the model of a graphite degrader has been developed with four Monte Carlo codes: three conventional Monte Carlo codes (FLUKA, GEANT4 and MCNPX) and the multi-purpose particle tracking code OPAL equipped with a simplified Monte Carlo routine. From the comparison between the different codes, we can deduce how the accuracy of the degrader model influences the precision of the beam dynamics model of a possible transport line downstream of the degrader.
1 August 2018
Optimization methodology for the global 10 Hz orbit feedback in RHIC
Publication date: 1 August 2018
Source:Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 898 Author(s): C. Liu, R. Hulsart, K. Mernick, R. Michnoff, M. Minty To combat beam oscillations induced by triplet vibrations at the Relativistic Heavy Ion Collider (RHIC), a global orbit feedback system was developed and applied at injection and top energy in 2011, and during beam acceleration in 2012. Singular Value Decomposition (SVD) was employed to determine the strengths and currents of the applied corrections. The feedback algorithm was optimized for different magnetic configurations (lattices) at fixed beam energies and during beam acceleration. While the orbit feedback performed well since its inception, corrector current transients and feedback-induced beam oscillations were observed during the polarized proton program in 2015. In this report, we present the feedback algorithm, the optimization of the algorithm for various lattices and the solution adopted to mitigate the observed current transients during beam acceleration.
1 August 2018
Study of point- and cluster-defects in radiation-damaged silicon
Publication date: 1 August 2018
Source:Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 898 Author(s): Elena M. Donegani, Eckhart Fretwurst, Erika Garutti, Robert Klanner, Gunnar Lindstroem, Ioana Pintilie, Roxana Radu, Joern Schwandt Non-ionising energy loss of radiation produces point defects and defect clusters in silicon, which result in a significant degradation of sensor performance. In this contribution results from TSC (Thermally Stimulated Current) defect spectroscopy for silicon pad diodes irradiated by electrons to fluences of a few $1 0 14$ cm
1 August 2018
Simulation and efficiency studies of optical photon transportation and detection with plastic antineutrino detector modules
Publication date: 1 August 2018
Source:Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 898 Author(s): Mustafa Kandemir, Altan Cakir In this work, the simulation of optical photons is carried out in an antineutrino detector module consisting of a plastic scintillator connected to light guides and photomultipliers on both ends, which is considered to be used for remote reactor monitoring in the field of nuclear safety. Using Monte Carlo (MC) based GEANT4 simulation, numerous parameters influencing the light collection and thereby the energy resolution of the antineutrino detector module are studied: e.g., degrees of scintillator surface roughness, reflector type, and its applying method onto scintillator and light guide surface, the reflectivity of the reflector, light guide geometries and diameter of the photocathode. The impact of each parameter is investigated by looking at the detected spectrum, i.e. the number photoelectrons per depositing energy. In addition, the average light collection efficiency of the detector module and its spatial variation are calculated for each simulation setup. According to the simulation results, it is found that photocathode size, light guide shape, reflectivity of reflecting material and wrapping method show a significant impact on the light collection efficiency while scintillator surface polishing level and the choose of reflector type show relatively less impact. This study demonstrates that these parameters are very important in the design of plastic scintillator included antineutrino detectors to improve the energy resolution efficiency.
21 July 2018
Non-proportionality of GAGG:Ce scintillators down to 50 eV electron equivalent by application of alpha particle excitation
Publication date: 1 August 2018
Source:Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 898 Author(s): Pawe
21 July 2018
Beam production of  18Ne with in-flight method for alpha scattering at CRIB
Publication date: 21 July 2018
Source:Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 897 Author(s): N.N. Duy, K.Y. Chae, S.M. Cha, H. Yamaguchi, K. Abe, S.H. Bae, D.N. Binh, S.H. Choi, K.I. Hahn, S. Hayakawa, B. Hong, N. Iwasa, D. Kahl, L.H. Khiem, A. Kim, D.H. Kim, E.J. Kim, G.W. Kim, M.J. Kim, K. Kwak, M.S. Kwag, E.J. Lee, S.I. Lim, B. Moon, J.Y. Moon, S.Y. Park, V.H. Phong, H. Shimizu, L. Yang, Z. Ge, T.V. Nhan Hao We conducted a measurement of  18Ne +