PURPOSE To provide a comprehensive investigation of electron beam reference dosimetry using Monte Carlo simulations of the response of 10 plane-parallel and 18 cylindrical ion chamber types. Specific emphasis is placed on the determination of the optimal shift of the chambers' effective point of measurement (EPOM) and beam quality conversion factors. METHODS The EGSnrc system is used for calc...

A guarded cylindrical graphite ionization chamber of nominal volume 1000 cm3 was designed and fabricated for use as a reference standard for low-dose rate 137Cs brachytherapy sources. The air kerma calibration coefficient (N(K)) of this ionization chamber was estimated analytically using Burlin's general cavity theory, as well as by the Monte Carlo simulation and validated experimentally using ...

An experimental determination has been made of the perturbation correction to be applied to a graphite cylindrical (thimble type) ionization chamber. The results indicate that the magnitude of this correction increases with depth and is closely related to the size of the cavity. This makes possible the use of such a chamber as an' excellent standard of absorbed dose in graphite for 60Co gamma r...

A new cylindrical low-mass central drift chamber has been constructed for the K + ! + experiment at BNL (E787). The chamber consists of 12 layers of axial wire cells and 6 layers of thin cathode-strip foils, four of which are supported by diierential gas pressure. The momentum resolution (RMS) for muons and pions in the range 150 to 250 MeV/c is found to be about 0.9%.

The hiARK III detector is shown in Figs. l(a) and l(b). The detector is described in Ref. 1 and its main subsystems are described in Refs. 2-6. Briefly, working out from the interaction point, the detector consists of an inner trigger chamber, followed by a large drift chamber, a time-of-flight (TOF) counter system, a gas sampling cylindrical shower counter, a solenoidal coil which generates an...

Abstract The cylindrical graphite cavity chambers are used for primary standard of air kerma rate of Co-60 and Cs-137. We measured wall attenuation correction factor (Kat) at several irradiation angles using extrapolation technique because of angular dependence. From these results, it can be seen that it is insufficient technique for evaluation of Kat. The Monte Carlo simulations were also done...

A numerical simulation of the Mechanofusion (MF) device, which is used for powder surface modification (dry particle coating, mixing, etc.), is carried out using the discrete element modeling (DEM) technique. An existing, widely used, cohesionless contact model (Walton– Braun) is used for two-dimensional simulation studies, in which the particles are assumed to be frictional, elastic-plastic sp...

The central drift chamber for the BaBar detector at the PEP-II Bfactory at SLAC is a cylindrical chamber with a length of 280 cm and outer radius of 81 cm. It consists of 40 layers of small hexagonal cells arranged in 10 axial and stereo super-layers. In order to minimize multiple scattering, light materials are used for the mechanical structure, and the gas mixture is Helium based. The pulse-h...