Estimation of the Most Probable Muon Energy at Sea Level Using Two-Paddle Cosmic Ray Detectors

We present a measurement of the most probable cosmic muon energy at near sea level using a two-paddle cosmic ray detector. Muon rates at two different elevations (27 and 326 m) were measured. Data were collected for 2-3 h for each data set at 1 min intervals in the afternoon of successive days. Muon counts were extracted from a Gaussian fit to the distributions of both sets. Despite the fact that only a limited amount of data were collected and measurements were performed at relatively close altitudes, we observed good agreement between the 2.28 +/- 0.21 GeV energy measured in this work and the value of 2 GeV that is reported in the literature

Aerogel Efficiencies of Threshold Cherenkov Counters

We present the aerogel efficiencies of the Cherenkov counters used as a sub-component of Bates large acceptance spectrometer toroid. The events of the elastic channel of electron-proton scattering from hydrogen is utilized. The counters' aerogel efficiencies change between (91.5 +/- 0.3) and (98.6 +/- 0.6)% based on a time-of-flight scintillation paddle. In addition, up to similar to 7 % variation in the local efficiencies per paddle is attributable to statistical fluctuations and no local inefficient aerogel pockets are encountered

Mass attenuation coefficients, effective atomic numbers and electron densities of some contrast agents for computed tomography

In the clinical computed tomography (CT) examinations, a photon is attenuated as it passes a patient by tissues and contrast agents (CAs). The CM can increase the visibility of internal structures or fluids within the patient. In this work, we have investigated the photon interaction parameters of some CT contrast agents such as iotrolan, iodixanol, iohexol, ioxilan, ioversol, and iomeprol. The mass attenuation coefficients (mu/rho) of these contrast agents have been determined using Geant4 code in the energy range from 1 keV to 1 MeV for total photon interaction. The validity of the Geant4 code was verified by comparing the simulation results with those calculated by the XCOM program. A very good agreement was observed between mu/rho values obtained by both Geant4 and XCOM codes. The mu/rho values were then used to estimate the effective atomic numbers (Z(eff)) and electron densities (N-eff) for the selected CT contrast agents. It was found that the values of mu/rho, Z(eff) and N-eff depend on the photon energy and increase with increasing iodine concentration in the composition of CAs. Also, the Z(eff) values were observed in the range of 6-50 and the N-eff values were observed in the range of 2 - 21 (10(23) electron/g). The present study would be helpful to develop new CT contrast agents to serve in vivo imaging applications

Study on gamma-ray buildup factors of bismuth borate glasses

Energy absorption buildup factor (EABF) and exposure buildup factor (EBF) of bismuth borate glass systems in structure (75-x)B2O3-xBi2O3-10Na2O-10CaO-5Al2O3 (0x25) have been investigated for photon energy region between 0.015 and 15 MeV and for penetration depths of 1-40 mfp. Five parameters (G-P) fitting method has been carried out for computations procedure. The calculated values of EABF and EBF have been observed to be dependent on photon energy, penetration depths and on the concentration of Bi2O3 mol% in the glass sample. It has been found that BOB25 glass offers better gamma-ray shielding than other samples. In addition, the values of EABF and EBF have been compared and significant differences up to 8% have been noted in intermediate energy region