To obtain accurate information for absorbed dose calculations in water kilovoltage x-rays, the photon spectrum, planar fluence and angular distribution of photons at collimator exit x-ray unit have to be known. The only way this is by Monte Carlo (MC) simulation. Compared with situation high-energy electrons, where recent years numerous papers been devoted MC modelling complete clinical accelerator units, there a lack similar work kV units. A reliable model would allow output used treatment...

Microbeam therapy is established as a general concept for brain tumour treatment. A synchrotron based x-ray source was chosen experimental research into microbeam therapy, and therefore new simulations were essential investigating the parameters with proper description of radiation characteristics. To design treatments, newly upgraded LSCAT (Low energy SCATtering) package EGS4 Monte Carlo simulation code adapted to develop an accurate self-written user calculating dose profiles precision 1...

The scattered-energy spectra of monochronized synchrotron-radiation photons toward 90\ifmmode^\circ\else\textdegree\fi{} by C, Al, Fe, Cu, Au, and Pb samples were measured using high-purity Ge detectors to obtain incoherent scattering function (S) in the 1.14x2.28-A${\mathrm{\r{}}}^{\mathrm{\ensuremath{-}}1}$ region. multiple-scattering intensity was evaluated a Monte Carlo calculation while considering Doppler broadening Compton-scattered photon linear polarization. S Cu agreed with that...

In a nuclear power plant accident, radioactive nuclides may be released which are distributed uniformly on the ground. If estimation of dose rate from such source by Monte Carlo calculation is attempted, some difficulty encountered because efficiency very low. To solve this low problem, we show that plane isotropic can transformed into point changing detector shape unit sphere to plane. We verified validity transformation numerical comparison unscattered photon fluence. As an example...

The frequency distribution of the lineal energy, y, a 290 MeV/u carbon beam was measured to obtain dose-weighted mean y and compare it with linear energy transfer (LET). In experiment, wall-less tissue-equivalent proportional counter (TEPC) in cylindrical volume simulated diameter 0.72 microm used. as well its dose-mean value agrees within 10% uncertainty corresponding data from microdosimetric calculations using PHITS code. ratio LET is 0.73, which much smaller than obtained by wall TEPC....

A radiophotoluminescent glass rod dosimeter (RGD) has recently become commercially available. It is being increasingly used for dosimetry in radiotherapy to measure the absorbed dose including scattered low-energy photons on body surface of a patient and postal audit. In this article, dosimetric properties RGD, energy dependence response, reproducibly, variation data obtained by RGD each energy, angular photons, are discussed.An (GD-301, Asahi Techno Glass Corporation, Shizuoka, Japan) was...

The frequency distributions of the lineal energy, y, 160 MeV proton, 150 MeV/u helium, and 490 silicon ion beams were measured using a wall-less tissue equivalent proportional counter (TEPC) with site size 0.72 µm. y as well dose-mean values, y(D), agree corresponding data calculated microdosimetric function particle heavy transport code system PHITS. values y(D) increase in range LET below ~10 keV µm(-1) because discrete energy deposition by delta rays, while relation is reversed above...

Glow curves of LiF TLDs (TLD-100) were measured for 10-40 keV monoenergetic photons from synchrotron radiation, and the energy dose responses evaluated based on glow curve data. The ratio to calculated response was almost unity lower temperature region including main peak, about 2.0 higher one. Dose 10 keV, 30 X rays, 60Co gamma rays showed different supralinearity. maximum value supralinearity decreased with decreasing photon energy, that is, increasing average linear transfer incident photons.

The energy spectra as well the angular distribution of photo-neutrons, called double differential cross sections (DDXs) (γ, xn) reaction were measured for 16.6 MeV linearly polarized photons on Pb, Au, Sn, Cu, Fe, and Ti targets. Polarized prepared using laser Compton scattering technique at BL01, NewSUBARU, Hyogo, Japan. photo-neutrons liquid organic scintillators, placed six different angles. time-of-flight was used to determine neutron energy. low high components DDXs identified all Flat...

A quasi-monoenergetic photon field with energy of ∼200 keV was obtained using a radioactive source backscatter layout. The layout allows the calibration dosimeter for two different energies single source. setup optimized through calculations and experiments to minimize low component obtain uniformity. optimal found comprise 1 × m2 steel floor, placed 20 cm above 10-cm cubic lead block directly Under proposed 208-MBq Cs-137 source, monoenergetic 190 ± 9.6 (FWHM) dose rate 3.18 0.18 µSv/h...

Time histories of the I-131 concentration in air at monitoring posts Fukushima prefecture March 2011 were estimated using pulse height distribution a NaI(Tl) detector, which was opened to public. Several corrections necessary owing high count rates. The contribution rates from accumulated around post on basis time history peak rate by method proposed authors. concentrations converted calculated response detector with egs5 for model plume containing uniformly. obtained fixed point first ones...

Organic photodiodes (OPDs) have attracted considerable interest in the field of photonic devices because they are useful for large and flexible photodetectors. To assess their applicability to radiation measurement, authors been studying response X-ray irradiation. For a previous study, OPDs with bulk heterojunction structure were fabricated. Then, X-rays was evaluated. However, X-ray-induced current extremely low necessity increase efficiency apparent. In this current, fabricated directly...

A method of deducing the I-131 concentration in a radioactive plume from time history peak count rates determined pulse height spectra obtained an NaI(Tl) scintillation detector employed as monitoring post was presented. The contribution to accumulated around subtracted accordance with history, taking into consideration cumulative attachment and its decay. concentrations plumes were estimated using calculated response egs5 for model uniformly containing I-131. This applied data posts at...

The neutron-emission spectrum from a 197Au target excited with 16.6 ±0.2 MeV, monoenergetic, linearly polarized photon beam was measured using the time-of-flight method at NewSUBARU-BL01. Two components were clearly detected in neutron produced by photonuclear reactions. One component [component (A)] shows an evaporation-like energies up to 4 MeV. of other (B)] is shaped like bump and ≥4 intensity (A) does not show any definite angular dependence, whereas, that (B) follows relation [a+ b...

Gamma-ray pulse-height distributions from widely distributed Cs-134 and Cs-137 calculated using the EGS5 Monte Carlo code with transformation of a system consisting plane isotropic source unit sphere detector into point were compared measured ones. Results agree well in terms both spectrum shape absolute value. Spectra at height 1 m I-131, studied by calculation. It was clarified that contribution scattered gamma rays is dominant within total gamma-ray flux. The contributions to ambient dose...

We measured the $L$ x-ray intensities of Pb, Au, and W for several different azimuthal angles partially polarized photon beams by using high-purity low-energy Ge detectors. utilized a monochromatized synchrotron beam as source. It had an energy $10.88--40\phantom{\rule{0.3em}{0ex}}\mathrm{keV}$, its degree linear polarization $P$ ranged from 0.84 to 0.89. The scattering polar angle $(\ensuremath{\theta})$ was 90\ifmmode^\circ\else\textdegree\fi{}, $({\ensuremath{\phi}}_{1})$...