Nobuteru Nariyama

Japan Synchrotron Radiation Research Institute (JASRI) · Beamline Optics Division

A microscope with band-pass filters was used to measure the optical-density distribution of GafChromic films irradiated with multi-slit microbeam X-rays. The planar width was 25 microm, and the center-to-center distance was 200 microm. The peak and valley dose rates in air were found to be 120 and 0.7Gy/s, respectively. In a polymethylmethacrylate...

The free-electron laser, first proposed by Madey(1) in 1971, has significantly reduced laser wavelengths to the vacuum ultraviolet(2,3) and soft X-ray regions(4). Recently, an X-ray free-electron laser (XFEL) was operated at 1.2 angstrom at the Linac Coherent Light Source (LCLS)(5). Here, we report the successful generation of sub-angstrom laser li...

Saturation curves for free-air ionization chambers with electrode gap widths of 4.2, 8.4 and 18 mm were obtained for 10 and 15 keV undulator synchrotron radiation thinned with a 230 Hz rotating-disk chopper. Ion recombination in free-air ionization chambers was found to be inversely proportional to the applied electric field, and an expression that...

In this study, double-multilayer monochromators that generate intense, high-energy, pink X-ray beams are designed, installed and evaluated at the SPring-8 medium-length (215 m) bending-magnet beamline BL20B2 for imaging applications. Two pairs of W/B4C multilayer mirrors are designed to utilize photon energies of 110 keV and 40 keV with bandwidths...

The relation between current and applied voltage of parallel-plate and free-air ionization chambers was investigated for high-intensity X rays from synchrotron radiation. To make pulsed X rays, synchrotron radiation was intercepted at 533 Hz with a rotating disk having slits. For continuous X rays, m decreased with applied voltage at parallel-plate...

This chapter provides fundamental and practical information on the use of ion chambers as detectors in X-ray absorption spectroscopy. Section 1 elucidates the function and limitations of ion-chamber detectors. In Section 2, the phenomenon of recombination in free-air ion chambers is explained using analytical expressions. Using these expressions, t...

Using battery-powered electronic neutron dosimeters, time-series neutron doses given by electron losses were measured above ID47 outside of storage ring for seven kinds of bunch filling patterns at SPring-8. After one-month measurements, the data were transferred to the personal computer. This procedures were repeated between 2016 April and 2018 De...

Neutron skyshine doses were calculated using a Monte Carlo code, FLUKA, by changing the heights and openings of shield walls. In the calculation geometry, the distance from the floor of the room to the roof was varied from 3 m to 10 m. The target into which electrons were injected was located at a height of 2.3 m. The distance between the shield wa...

Purpose: Scanning of dosimeters facilitates dose distribution measurements with fine spatial resolutions. This paper presents a method of conversion of the scanning results to water-dose profiles and provides an experimental verification. Methods: An Advanced Markus chamber and a diamond detector were scanned at a resolution of 6 μm near the bea...

For higher accuracy and efficiency of high radiation doses measurements, calibration functions with less numbers of parameters were applied to the measured intensity of EBT3 and HD-V2 GafChromic films irradiated with 60Co rays. Three calibration points were necessary up to 20 Gy for EBT3, and five calibration points were necessary up to 18 kGy for...

Substantial upgrades have been made to the beamline BL25SU at SPring-8 for soft X-ray imaging and spectroscopy of solid-state materials. The upgraded beamline consists of two branches: a micro-beam branch with high energy resolution, and a nano-beam branch with small angular divergence. The beamline has been available for use since October 2014, fo...

A tapered undulator beamline BL36XU was constructed at SPring-8 to conduct structural and electronic analysis of dynamic events on polymer electrolyte fuel cell (PEFC) cathode catalysts for the development of next-generation PEFCs. BL36XU provides various time and spatially resolved XAFS techniques in an energy range from 4.5 to 35 keV for investig...

Single-scattered X-ray doses at 1 m from silicon, copper and lead targets were calculated using an analytical point-kernel method considering the self-absorption, and the calculated values were compared with detailed results of a Monte Carlo calculation with respect to the emission angle. In the calculations, a slab slanted at 3° to the beam axis w...

The allowable electron energies of the linac in the RFgun test facility were increased from 30 MeV to 100 MeV in the past few years. The beamline branches near the bottom, and the branched beamline is angled at 30° to the side wall. As the background data for radiation safety, photon and neutron dose equivalent distributions around the lead and iro...

Doses for broad x-rays obliquely incident on slabs of concrete and iron backed by lead were calculated using photon/electron transport Monte Carlo codes. The results showed that the dose transmission in concrete with a thickness t can be expressed as D = D0 e− μ′t ’t at cos θ = 0.01 and 0.1 between 0.2 and 1 MeV where θ is the incident angle, D0 is...

An ionization chamber with four concentric ring electrodes was used to measure doses of white, 10, 15 and 20 keV synchrotron X-ray beams. The ring-shaped electrodes, which had diameters less than 11.8 mm, collected charges independently only around the beam, excluding strong in-beam charges when the beams passed through a small hole in the electrod...

A Monte Carlo simulation was applied to study the energy dependence on the transverse dose distribution of microplanar beam radiation therapy (MRT) for deep-seated tumors. The distribution was found to be the peak (in-beam) dose and the decay from the edge of the beam down to the valley. The area below the same valley dose level (valley region) was...

A new soft X-ray beamline, BL07LSU, has been constructed at SPring-8 to perform advanced soft X-ray spectroscopy for materials science. The beamline is designed to achieve high energy resolution (E/ΔE> 10000) and high photon flux [>10(12) photons s(-1) (0.01% bandwidth)(-1)] in the photon energy range 250-2000 eV with controllable polarization. To...

The newly installed BL28XU beamline at SPring-8 is dedicated to in situ structural and electronic analysis of rechargeable batteries. It supports the time range (1 ms to 100 s) and spatial range (1 µm to 1 mm) needed for battery analysis. Electrochemical apparatus for battery charging and discharging are available in experimental hutches and in a p...

To upgrade a safety interlock system, a restricted area was converted into an accessible area at an operating condition. To judge the necessity for an additional shield design, gamma-ray and neutron dose distributions were measured in the linac, booster synchrotron, L3BT, and New SUBARU (NS) areas. In the linac, chicane was found to be the main sou...

Radiotherapy is one of the most powerful treatments for brain tumor. Penetrating ionizing particles is aimed toward the tumor, delivering as high radiation to it as is usefully suppressive of tumor growth, and tolerated by normal vital tissues inevitably irradiated with the tumor. The use of a high-energy synchrotron-radiation thin X-ray beams (mic...

We upgraded the hard X-ray spectroscopy beamline BL39XU at SPring-8 by installing Kirkpatrick-Baez mirrors to equip it with submicron-focusing capability. At the new experimental end-station located 74 m from the undulator source, an X-ray nanoprobe with a size of 120 × 100 nm2 has become available at 5-16 keV. This upgrade is fully compatible with...

We have developed a fast scanning microscopic X-ray absorption fine-structure (XAFS) measurement system using a 100-300 nm focused X-ray beam at the BL39XU nano-scale analysis station at SPring-8. This system provides two-dimensional XAFS images constructed from X-ray fluorescence (XRF) images measured by fast continuous 2-dimensional scanning at a...

We are currently constructing a new X-ray absorption fine structure (XAFS) beamline BL36XU at SPring-8 dedicated for the structural and electronic analysis of the dynamic events on polymer electrolyte fuel cell (PEFC) cathode catalysts for the development of next-generation PEFCs. To investigate the cathode catalyst nanoparticles in PEFCs under the...

Advanced nano-scale analyses such as x-ray absorption fine structure (XAFS), x-ray magnetic circular dichroism (XMCD) spectroscopy and x-ray fluorescence (XRF) with a ~100 nm spatial resolution have been routinely conducted by upgrading two x-ray beamlines BL37XU and BL39XU at SPring-8. The focusing beam size can be varied from 50 nm to 2 μm and hi...

An electron beam halo monitor using diamond-based detectors, which are operated in the ionization mode, has been developed for the SPring-8 Angstrom compact free-electron laser (SACLA) to protect its undulator magnets from radiation damage. Diamond-based detectors are inserted in a beam duct to measure the intensity of the beam halo directly. To su...

At the straight sections in the storage ring of electron accelerators, gas bremsstrahlung X rays are emitted. The X-ray doses scattered at the absorbers of the front end were calculated using a Monte Carlo code with and without a lead local shield. The collimator shield was found to contribute to the dose reduction on the ratchet. For electron loss...

To gain a better understanding of the function of soft-material thin films, one should investigate the multiscale structural information from the surface roughness down to the atomically truncated structures at microarea. To achieve such an integrated investigation, a new experimental system has been launched by coupling with the measurement techni...

Photon and neutron doses around the L2 and L3 electron beam dumps in SPring-8 were calculated with a Monte Carlo code FLUKA. In the calculations, 1-GeV electrons were incident to each dump. For the L2 dump, the doses at the exit of the penetration holes for Synchrotron and L3BT were the critical points to set the additional shields when the safety...

Using a diamond-based detector, the electron beam halo in a high-energy accelerator can be measured with a lower detection limit than that using other instruments, such as a core monitor, a dose meter, or an optical fiber. We have successfully measured an electron beam halo using diamond-based detectors operating in the ionization mode, which were...

Current saturation characteristics of free-air ionization chambers with electrode gaps of 4.2 and 8.4 mm were investigated using pulsed photon beam obtained by periodically interrupting synchrotron radiation beams with a chopper. Pulsed photon beams of 10 and 15 keV with pulse duration of 2.5 mu s and a frequency of 230 Hz were produced by chopping...

Charge-coupled device (CCD) digital cameras have been used to expand the application area of conventional dosimeters to two-dimensional dose measurements. Although film dosimeters are normally read with scanners, CCD reading has several advantages over scanner reading: quick reading, interference filters, and no influence from the film orientation...

Knowledge of dose distribution with micron resolution is required in radiation therapy studies that use a spatially fractionated X-ray microbeam. However, the condition of the collimator affects the dose distribution. To estimate the performance of a modified collimator, the measured dose distribution was compared with that of a Monte Carlo PENELOP...

This is a text for beginners written in Japanese language.

We report the design and current status of a soft X-ray beamline BL07LSU with a 27-m-long undulator at SPring-8. The long undulator consists of eight figure-8 undulator segments, and generates circularly and linearly polarized soft X-rays. This beamline covers a wide energy range (250–2000eV) with both high energy resolution and high photon flux. C...

BL37XU (trace element analysis beamline) and BL39XU (magnetic materials beamline) at SPring-8 have been upgraded to provide nano-probe analysis. We designed and installed Kirkpatrick-Baez (KB) mirrors and corresponding manipulators, which have an X-ray focusing beam as small as 100 nm. To realize a high-flux 100-nm focusing beam, a high-demagnifica...

Radiation safety interlock system for the SPring-8 accelerator complex, which protects personnel from radiation hazard induced by electron beams and synchrotron radiation, has been operating over a decade. In the past 10years, the accelerator was upgraded to extend accelerator/beam-transport areas, and it was implemented new functions. The safety i...

The tumoricidal mechanisms of microbeam radiation therapy, and the more recently proposed minibeam radiation therapy, for the treatment of brain tumors are as yet unclear. Moreover, from among the various parameters of beam geometry the impact of changing the beam width is unknown. In this study, suppression of tumor growth in human glioma cells im...

Scientific and engineering research on soft materials requires precise structural analysis to understand their hierarchical and fluctuating nature. A new beamline, the BL03XU frontier soft-material beamline, that is dedicated to scattering experiments on soft materials was recently installed at the third-generation synchrotron facility, SPring-8, i...

High-dose radiation destroys cancer cells in radiation therapy. Verification imaging is performed to adjust the patient's position to precisely target the tumor. We have applied a refraction contrast imaging technique to verification imaging to improve the accuracy of radiation treatment. The edge enhancement effect in refraction contrast imaging c...

SACLA (SPring-8 Angstrom Compact free electron Laser), which comprises an 8 GeV linear accelerator and undulators, was constructed. Its radiation safety interlock system was designed to protect personnel from radiation hazards. This system controls access to an accelerator tunnel and monitors safety devices. It controls permission signals for accel...

The diamond-based beam halo monitor has been developed by the Safety Design Group with the collaboration of the Insersion Devise Team for SPring-8 Angstrom Compact free electron LAser (SACLA). This monitor can be used as an interlock sensor to protect the undulator magnets against radiation damage. To reduce the degradation of electron beam due to...

XFEL/SPring-8 is an X-ray laser facility currently being constructed in Japan. The facility consists of an 8-GeV electron linac, in-vacuum undulators and experimental beamlines. The safety interlock system of XFEL, which controls personnel access and radiation containment for protection from prompt radiation hazard, was designed to match that of SP...

The accelerator safety interlock system (ASIS) for XFEL/SPring-8 protects personnel from radiation hazards. The ASIS consists of three independent systems: central, emergency, and beam-route interlocks. If the ASIS detects an unsafe status, it turns off the permission signal for accelerator operation, thereby stopping the electron beams. The delay...

The beam halo monitor using diamond detectors, which are operated in photoconductive mode, has been developed for the X-ray free electron laser facility at SPring-8 (XFEL/SPring-8) to protect the undulator magnets against radiation damage. Pulse-by-pulse measurements are adopted to suppress the background noise efficiently, and to improve the detec...

A beam halo region of an electron beam at a linear accelerator might hit the undulator magnets and degrade undulator permanent magnets. An interlock sensor is indispensable to protect the magnets against radiation damage. We have been developing an electron beam halo monitor using diamond detectors for an interlock sensor at the X-ray free electron...

An electron beam halo monitor has been developed in order to protect undulator permanent magnets against radiation damage for the X-ray free electron laser facility at SPring-8 (XFEL/SPring-8). The halo monitor will be installed at the upstream of the undulator and detect the electron beam that might hit the undulator magnets. Diamond detector, whi...

The accelerator safety interlock system (ASIS) for the X-ray free electron laser (XFEL) at SPring-8 protects personnel from radiation hazards. We developed an ASIS consisting of three interlock systems: a central interlock system (CIS), an emergency interlock system (EIS), and a beam route interlock system (BIS). The CIS and EIS monitor the safety...

A) JASRI/SPring-8 Joint Project for XFEL 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198 B) RIKEN/SPring-8 Joint Project for XFEL 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148 Abstract An electron beam halo monitor using diamond detectors has been developed as an interlock sensor, in order to protect the permanent magnets of undulators agains...

To determine whether glioma cells irradiated with a microplanar X-ray beam exert bystander effects. Microplanar beam irradiation of glioma cells in vitro was done using the SPring-8 synchrotron radiation facility. The amount of DNA double-strand breaks (dsbs) was measured by the fluorescence intensity of phosphorylated H2AX or the number of 53BP1 f...

We have been developing an electron beam halo monitor as an interlock device for protection of undulator permanent magnets against radiation damage. When permanent magnets are irradiated with a halo part of 8GeV electron beam, magnetic fields undulators are degraded permanently and laser oscillation is weakened. Therefore, the interlock device is r...

In the book "Detector Guide for Synchrotron Radiation Users" (ISBN 978-4-06-153276-2) 2. Ionization Chamber 2.1 Principle and characteristics 2.2 Composition of the detector and the measuring method 2.3 Application examples 2.4 Summary and prospect 3. Film dosimeters 3.1 Principle and characteristics 3.2 Composition of the detector and the measuri...

The proportion of high-harmonic components included in monochromatized synchrotron radiation was measured with a combination of two free-air ionization chambers. The absolute intensity of the fundamental photons was measured with a chamber having a narrow gap. For the high harmonics, the intensity attenuated through a foil set to remove the fundame...

GafChromic films have been used at SPring-8 to detect the intensively irradiated parts and protect them from damage by being covered with shield or moved. To extend the usable dose range more widely, a new type of sensitive film EBT was investigated for the introduction. Calibration curves were obtained irradiated with 60Co gamma rays and compared...

Radiation damage is an important problem in accelerator facilities. At SPring-8, a high-dose dosimetry system was introduced to measure the dose distribution in the storage ring and beamline hutches. At the storage ring, dose distribution was measured with GafChromic films HD-810 and MD-55, which detected the local areas irradiated with excessive s...

Photoluminescence (PL) of a Si-doped polycrystalline diamond film fabricated using the chemical vapor deposition technique was employed to measure the profile of a synchrotron radiation pink x-ray beam emitted from an in-vacuum hybrid undulator at the SPring-8 facility. The spectrum of the section of the diamond film penetrated by the emitted visib...

The SPring-8 Storage Ring has been operated since 1997, and the integrated electron beam dose was achieved over 2750 A•hr. Electric cables have been irradiated with the high-intense scattered X-ray from photon absorber, and are damaged. Then we measured the absorbed dose along the laying route of radiation damaged ion pump cable, and compared the r...

Sauter expression is often used for photoelectron angular distribution in photon/electron transport codes. The expression is known to show too forward peak for high-Z materials. Monte-Carlo simulations of electron transmission and reflection to 662-keV photons for lead revealed that Sauter expression overestimated electron transmission and underest...

The saturation characteristics of two sizes of parallel-plate free-air ionization chambers were investigated for synchrotron radiation at bending-magnet, wiggler and undulator beamlines of SPring-8. The gaps of the electrodes were 4.2 and 85 mm. The monoenergetic photon energies ranged from 10 to 115.56 keV and the air kerma rates from 0.2 mGy s-1...

A 6LiF-rich thermoluminescent sheet-type dosemeter (6LiF-rich NTL sheet) was developed for neutron 2D dosimetry. The dosemeter utilises the 6Li(n, α)3H reaction to detect thermal neutrons. Responses of the 6LiF-rich NTL sheet to neutrons were measured at the neutron beam irradiation facility for BNCT in JRR-4 Research Reactor at the Japan Atomic En...

To measure dose distribution for X- and gamma rays simply and accurately, a tissue-equivalent thermoluminescent (TL) sheet-type dosemeter and reader system were developed. The TL sheet is composed of LiF:Mg,Cu,P and ETFE polymer, and the thickness is 0.2 mm. For the TL reading, a square heating plate, 20 cm on each side, was developed, and the temp...

A 2-D tissue-equivalent sheet-type dosemeter (NTL sheet) was developed using thermoluminescent material of LiF:Mg,Cu,P (NTL-250). The energy responses of the NTL sheet and NTL-250 powder were measured with 10–150 keV monoenergetic photons from synchrotron radiation at SPring-8. The sample was irradiated by a rotational method for the uniform irradi...

We have developed a new method for high radiation dose rate monitoring based on cavity ring-down laser absorption spectroscopy and have measured Co gamma-ray induced chemical species in stationary and flowing air at the wavelength of 532 nm to check the basic performance of the new method. In the stationary air measurement, we confirmed linearity b...

A user code of EGS4, UCBEAM was developed to analyze local exposures and to facilitate the data input preparation. This code can calculate both the organ doses and the absorbed dose distribution, using EGS4 and GSF formatted voxel phantom. An experiment was performed in SPring-8 using a resin phantom. The phantom shape is torso with a head simulati...

Using 10 and 30 keV photons from synchrotron radiation, we measured optical density curves of GafChromic films MD-55 and HD-810 and compared the results with those of (60)Co gamma rays up to 500 kGy. The scanners used were a fluorescence digitizer and a color film scanner. In addition, the energy responses were measured between 10 and 100 keV. The...

A secondary electron emission detector can be used as a high-intensity radiation beam monitor because the absence of ion recombination extends the upper dose range of the monitor. The characteristics of saturation, linearity, sensitivity, reproducibility, and current stability of the monitor were measured with respect to synchrotron radiation from...

Energy response of LiF:Mg,Ti, LiF:Mg,Cu,P and Mg2SiO4:Tb thermoluminescence dosemeters (TLDs) was measured in the range 10–150 keV for monoenergetic photons at SPring-8 of an 8-GeV synchrotron radiation facility. The photon beam was monitored by a parallel-plate free-air ionisation chamber calibrated with an uncertainty of 3%. Owing to the small di...

Synchrotron radiation is a high-intensity x-ray beam. The in-situ absolute intensity measurement is important for various experiments. At SPring-8 of a large-scaled synchrotron radiation facility, we have developed a parallel-plate free-air ionization chamber for photons up to 150 keV from a bending magnet and the uncertainty was confirmed within 3...

For dose rate monitoring in high level radiation fields, we have proposed a concept of novel dose rate monitoring method based on high sensitive laser absorption spectroscopy technique for radiation induced chemical species. The yield of the species depends on the intensity of the radiation field. The dose rate of the radiation field, therefore, ca...

In order to develop an absolute intensity monitor for synchrotron radiation from an undulator, the characteristics of a parallel-plate free-air ionization chamber with a plate separation of 4.2 mm, which was considered to be as narrow as possible, were investigated using 8–30 keV monoenergetic photons at SPring-8. Using a Si-PIN photodiode as the r...

At SPring-8, intense monitor for synchrotron radiation has been developed. Using the monitor, response of radiation detectors and dosimeters to monoenergetic photons can be measured. In the most cases, uniform irradiation to the sample is necessary and so two scanning methods were proposed. One is an XZ-linear scanning method, which moves the sampl...

Thermoluminescence dosimetric characteristics of K2YF5 crystals doped with Pr3+ are reported for the first time. The efficiency of the 0.5 at.% Pr3+ doped K2YF5 crystal has been found to be maximum for this concentration series and three times higher than that of the commercial dosimeter TLD-700. The thermoluminescence glow curve of this novel phos...

As an intensity monitor for high-energy synchrotron radiation, a parallel-plate free-air ionization chamber was developed. An EGS4 Monte-Carlo transport calculation considering linear polarization showed that the electron escape fraction was within 0.5% below 70keV, 2.7–3.3% below 150keV and 1.1% at 150keV when the plate separation was 8.5cm. Witho...

At SPring-8, photon intensity monitors for synchrotron radiation have been developed. Using these monitors, the responses of radiation detectors and dosimeters to monoenergetic photons can be measured. In most cases, uniform irradiation to the sample is necessary. Here, two scanning methods are proposed. One is an XZ-linear scanning method, which m...

The saturation characteristics of the free-air ionization chamber (FAIC) and Si PIN photodiode were measured for intense synchrotron radiation (SR) beam at KEK-PF and SPring-8. The saturation phenomenon of FAIC increased rapidly with the SR intensity above 1 x 10¹¹ [photon/sec]. For the Si PIN photodiodes (SPPD) it could not be observed, but SPPD s...

In usual personal dosimetry, whole body irradiation is assumed. However, the opportunity of partial irradiation is increasing and the tendencies of protection quantities caused under those irradiation conditions are different. The code system has been developed and effective dose and organ absorbed doses have been calculated in the case of horizont...

To measure continuous dose distribution for gamma and x rays, a tissue-equivalent thermoluminescent (TL) thin sheet-type dosimeter and the reader system were developed. The TL sheet is made of LiF:Mg,Cu,P mixed with polymer ETFE and the thickness is 0.2 mm. The energy response calculated showed excellent tissue-equivalent property. For the TL readi...

To estimate local dose given by synchrotron radiation and radiation through shield defect, dose distribution measurement using a human phantom is planned. For the measurement, it is preferable that dosimeters inserted in the phantom are equivalent to each organ material. For the estimation, mass energy-absorption coefficients were compared between...

An attractive advantage of SPring-8 is that a monoenergetic photon beam up to 100 keV energy region is available at bending-magnet beamlines. High-energy X-rays with an excellent energy resolution are not available by conventional X-ray machine and non-large-scale synchrotron radiation facilities. For applications of a unique photon beam, an absolu...

Energy deposition in two-sized parallell-plate free-air ionization chambers was calculated for 30-200 keV photons with EGS4 to estimate the electron escape fraction for the chambers. For the low-energy x-ray ionization chamber of 5-cm plate separation, the escape increased with energy to 70 keV, decreased from 70 to 100 keV, and above 150 keV rose...

Optical and dosimetric properties of nominally pure CsGd2F7 crystals and of CsGd2F7 crystals doped with various concentrations of Pr3+ ions were investigated. Effects of X, beta and UV irradiation on these crystals were studied. Methods of optical absorption, X and UV excited luminescence, thermoluminescence (TL), phototransferred thermoluminescenc...

Synchrotron radiation has been increasingly and extensively used for materials science, biology and medical research. For measurement of high dose from the low energy photons, tissue-equivalent dosemeters having linearity in the Gy region are required. In this study, energy and dose responses of double-layer Gafchromic film MD-55 were measured usin...

Saturation characteristics of Si photodiode (Hamamatsu S5377), free air ionization chamber (FAIC) and BGO scintillator for intense synchrotron radiation beam were measured with varying the thickness of Al absorber at the undulator beamline BL46XU in SPring-8. The FAIC showed serious saturation owing to the recombination when the beam intensity exce...

For angiography using synchrotron radiation we measured the absorbed dose distribution in inhomogeneous phantoms with thin LiF:Mg, Cu, P, LiF:Mg, Ti thermoluminescent dosimeters (TLDs) in tissue and lung substitutes, and with Mg2SiO4:Tb TLDs in bone substitute for 33.32 keV monoenergetic photons from synchrotron radiation. The energy responses of t...

Coronary cineangiography using synchrotron radiation is anticipated, owing to the high intensity and availability of monoenergy. To investigate allowable dose levels in clinical application, absorbed dose distribution in a tissue substitute phantom for a conventional x-ray machine was measured with thermoluminescent dosimeters at the University of...

To investigate the simulation of ionization process by synchrotron radiation, energy deposition by electrons reflected from gold irradiated with photons was calculated with a Monte Carlo transport code ITS and compared with measured backscattering factors for 10–40 keV monoenergetic photons from synchrotron radiation. The calculated factors almost...