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Microbeam radiation therapy (MRT) utilizes highly collimated synchrotron generated x-rays to create narrow planes of high dose radiation for the treatment of tumors. Individual microbeams have a typical width of 30-50 µm and are separated by a distance of 200-500 µm. The dose delivered at the center of the beam is lethal to cells in the microbeam path, on the order of hundreds of Grays (Gy). The tissue between each microbeam is spared and helps aid in the repair of adjacent damaged tissue. Radiation interactions within the peak of the microbeam, such as the photoelectric effect and incoherent (atomic Compton) scattering, cause some dose to be delivered to the valley areas adjacent to the microbeams. As the incident x-ray energy is modified, radiation interactions within a material change and affect the probability of interactions, as well as the directionality and energy of ionizing particles (electrons) that deposit energy in the valley regions surrounding the microbeam peaks. It is crucial that the valley dose between microbeams be minimal to maintain the effectiveness of MRT. Using a monochromatic x-ray source with x-ray energies ranging from 30 to 150 keV, a detailed investigation into the effect of incident x-ray energy on the dose profiles of microbeams was performed using samarium doped fluoroaluminate (FA) glass as the medium. All dosimetric measurements were carried out using a purpose-built fluorescence confocal microscope dosimetric technique that used Sm-doped FA glass plates as the irradiated medium. Dose profiles are measured over a very a wide range of x-ray energies at micrometer resolution and dose distribution in the microbeam are mapped. The measured microbeam profiles at different energies are compared with the MCNP6 radiation transport code, a general transport code which can calculate the energy deposition of electrons as they pass through a given material. The experimentally measured distributions can be used to validate the results for electron energy deposition in fluoroaluminate glass. Code validation is necessary for using transport codes in future treatment planning for MRT and other radiation therapies. It is shown that simulated and measured micro beam-profiles are in good agreement, and micrometer level changes can be observed using this high-resolution dosimetry technique. Full width at 10% of the maximum peak (FW@10%) was used to quantify the microbeam width. Experimental measurements on FA glasses and simulations on the dependence of the FW@10% at various energies are in good agreement. Simulations on energy deposited in water indicate that FW@10% reaches a local minimum around energies 140 keV. In addition, variable slit width experiments were carried out at an incident x-ray energy of 100 keV in order to determine the effect of the narrowing slit width on the delivered peak dose. The microbeam width affects the peak dose, which decreases with the width of the microbeam. Experiments suggest that a typical microbeam width for MRT is likely to be between 20-50 µm based on this work.

Microbeam Radiation Therapy (MRT) is a promising cancer treatment technique. During the treatment, a micro-planar lattice of narrow X-ray beams called a microbeam (each narrow X-ray beam is typically 20–100 μm wide separated by 100–400 μm) delivers a very large dose (>1000 Gy) onto a tumor. Sm3+-doped glasses that involve the reduction of the Sm-valency (Sm3+ → Sm2+) upon X-ray irradiation are one of the potential dosimetric detectors for this particular application. With this class of detectors, we use the extent of valency reduction as a measure of the delivered X-ray dose, and the response read out using a confocal microscopic technique via the Sm2+/Sm3+ photoluminescence. This method enables us to measure the dose distribution of the microbeam. In this paper, we show that both Sm3+-doped fluorophosphate and fluoroaluminate glasses exhibit a dynamic range for the conversion response from 1 to over 1000 Gy, which satisfies the dose range for MRT applications. The dynamic range depends on the concentration of Sm3+ dopants as well as the detector glass composition. Moreover, X-ray induced absorbance, photobleaching and thermally-stimulated luminescence (TL) measurements suggest that the hole trapping process during X-ray irradiation is a dominant factor for the valency conversion, and the accommodation of precursor POHCs in fluorophosphate glasses gives rise to an acceleration of the conversion process.

highlights < Formation of transparent Ba0.3Sr0.7Cl2 in polycrystalline form. < X-ray phosphor materials with a resolution of at least 6 LP/mm. < Energy discrimination achieved with 'phoswich' structure based on emission wavelength. < Dual energy imaging technique allowing composition-sensitive imaging. abstract Polycrystalline solid state solutions of BaySr1 � yCl2 have been produced; these adopt the cubic fluorite phase for y � 0.30. The cubic structure minimizes optical scattering from grain boundaries, and so for y � 0.30 the materials are transparent, a key advantage for ceramic scintillators and phosphors. The substitution of Sr 2þ ions with Ba 2þ ions has the advantage that it substantially increases the x-ray ab- sorption coefficient with respect to pure SrCl2. Additional doping with rare earth ions such as Sm 2þ and Eu 2þ gives bright x-ray phosphor materials. The Sm or Eu-doped materials show a broad 4f 5 5d 1 / 4f 6 emission peaked at 685 nm or a broad 4f 6 5d 1 / 4f 7 emission peaked at 406 nm respectively. These materials have been tested as x-ray phosphors and the spatial resolution was determined to be at least 6 LP/mm, whilst the x-ray radioluminescence intensity is around 40% that of the commercial x-ray phosphor Gd2O2S:Tb. A stratified phoswich structure, comprising Eu and Sm-doped layers of BaySr1 � yCl2 was produced in which the relative intensities of the two emissions varies with x-ray beam energy; this can be used for energy discrimination in imaging by way of emission spectra as opposed to the more commonly used pulse shape discrimination. A dual energy imaging technique based on these bi-layered structures and utilizing a semi-professional grade digital SLR camera is described and composition- sensitive imaging has been demonstrated.

2 þ Computed radiography abstract The recent advancements in consumer-grade digital camera technology and the introduction of high- resolution, high sensitivity CsBr:Eu 2 þ storage phosphor imaging plates make possible a new cost- effective technique for X-ray imaging. The imaging plate is bathed with red stimulating light by high- intensity light-emitting diodes, and the photostimulated image is captured with a digital single-lens reflex (SLR) camera. A blue band-pass optical filter blocks the stimulating red light but transmits the blue photostimulated luminescence. Using a Canon D5 Mk II camera and an f1.4 wide-angle lens, the optical image of a 240 � 180 mm 2 Konica CsBr:Eu 2 þ imaging plate from a position 230 mm in front of the camera lens can be focussed so as to laterally fill the 35 � 23.3 mm 2 camera sensor, and recorded in 2808 � 1872 pixel elements, corresponding to an equivalent pixel size on the plate of 88 mm. The analogue-to-digital conversion from the camera electronics is 13 bits, but the dynamic range of the imaging system as a whole is limited in practice by noise to about 2.5 orders of magnitude. The modulation transfer function falls to 0.2 at a spatial frequency of 2.2 line pairs/mm. The limiting factor of the spatial resolution is light scattering in the plate rather than the camera optics. The limiting factors for signal-to-noise ratio are shot noise in the light, and dark noise in the CMOS sensor. Good quality images of high-contrast objects can be recorded with doses of approximately 1 mGy. The CsBr:Eu

The role of planners is commonly examined in the context of local government decision-making processes. However, planners also participate in other institutional contexts. This article examines planners' roles in merits appeals in two jurisdictions in Australia. The author finds that planners carry out numerous functions in development assessment appeals—they participate as advocates, expert witnesses and decision-makers. However, these roles are not static. They tend to vary depending on the procedural model utilised by the tribunal or court. This article examines the different ways that planning expertise is employed in the Land and Environment Court (NSW) and the Victorian Civil and Administrative Tribunal.

We report the optical properties of a fluorochlorozirconate (FCZ) glass with the composition 53% ZrF 4 , 20% NaF, 3.5% AlF 3 , 3% LaF 3 , 0.5% InF 3 , (20 − x )% BaCl 2 , x % BaF 2 with x varying from 0% to 2%, and doped with various amounts of trivalent erbium by the addition of ErCl 3 . Annealing of the as-prepared glass in inert (N 2 ) or reducing (5%H 2 + 95%Ar) atmospheres at temperatures that ensure the conversion of the glass into a glass-ceramic by the nucleation of BaCl 2 nanocrystals, does not significantly change any of Er 3+ related absorption and photoluminescence (PL) characteristics. We have carried out a Judd–Ofelt analysis of the absorption spectra and obtained Ω 2 = (1.92 ± 0.3) × 10 − 20 cm 2 , Ω 4 = (0.88 ± 0.16) × 10 − 20 cm 2 and Ω 6 = (0.59 ± 0.08) × 10 − 20 cm 2 , and also the radiative lifetimes of the 4 I 13/2 → 4 I 15/2 , 4 I 11/2 → 4 I 15/2 and 4 S 3/2 → 4 I 15/2 bands. The radiative lifetime from the Judd–Ofelt analysis for the 4 I 13/2 → 4 I 15/2 band is in good agreement with the experimentally measured PL decay time. The examination of the optical properties of powdered samples with different average particle size does not show any photon trapping effects. We have determined the spectral absorption and emission cross-sections and then estimated the possible spectral optical gain for varying degrees of relative populations of the 4 I 13/2 and 4 I 15/2 manifolds.

Optical absorption, optically stimulated luminescence, and thermo-luminescence measurements have been made on RbCdF3:Mn2+ single crystals with the aim of characterizing this compound for holographic storage. We show that there are stable traps that are filled after deep ultra-violet irradiation (

We report the results from photo-luminescence (PL) measurements on single crystal RbCdF3 doped with up to 1% Mn2+, before and after X-ray and deep UV irradiation. The intensity of the Mn2+ PL emission at 560 nm increases with increasing X-ray or UV (

The spatial resolution of a glass-ceramic X-ray storage phosphor imaging plate has been measured using a scanned and focussed laser beam. The glass ceramic comprises orthorhombic phase barium chloride crystals containing europium ions embedded in a fluorozirconate glass matrix. The modulation transfer function extends to significantly higher frequencies than for a commercial imaging plate based on powdered BaFBr:Eu crystals; the modulation transfer function falls to a value of 0.3 at 10 lp/mm compared to 2 lp/mm for the commercial plate. The modulation transfer function has a bimodal character which we ascribe to component responses from the focussed laser beam volume and from the surrounding scattering halo. A limitation on performance of this particular glass ceramic is the occurrence of bubbles and other defects which scatter the read-out light beam and reduce the uniformity of the response.

We analyse measurements of the optical extinction coefficient for fluorozirconate glasses containing a volume fraction of ∼0.2 of barium chloride nano-particles. We find that the glass ceramics are about a factor of six more transparent than predicted by Rayleigh scattering theory, based on estimates of particle sizes from X-ray diffraction and electron microscopy measurements. A numerical simulation of scattering using the discrete-dipole approximation has been made in order to investigate whether this particular discrepancy, and the “ultra-transparency” observed in other glass ceramics in general, can be explained by particle proximity and interaction effects as has been proposed in the literature. The simulated scattering system behaves essentially as a collection of independent scatterers up to a volume fraction of at least 25%, and so these effects are not responsible for the high transparency in this system.

We report on a photostimulated luminescence (PSL) effect in Ce-doped fluorobromozirconate glasses. Small hexagonal or orthorhombic BaBr2 crystallites are formed in the glass upon annealing. The PSL shows a (381,415) nm doublet which is due to the 5d–4f luminescence of Ce3+ in the orthorhombic BaBr2 crystallites embedded in the glass matrix. The stimulation band of the PSL peaking at 580 nm is probably due to perturbed F centres in the crystallites. After X-irradiation the magnetic circular dichroism of the optical absorption showed a broad band in the spectral range between 440 and 800 nm , having a derivative-like line shape centred at about 600 nm . The spectrum consists of two overlapping bands: one, derivative-like, belongs probably to F-centres, whereas the second band, superimposed on the low-energy region of the F-centre band, is due to a hole centre.

The turbidity, photoluminescence, and photo-stimulated luminescence (PSL) of fluorozirconate glass containing barium chloride nano- and micro-crystals have been measured for samples prepared by isochronal (70 min ) annealing over a temperature range of 220–283°C, and correlated with the microstructure as determined by X-ray diffraction measurements. Crystallization of hexagonal phase barium chloride commences at around 220°C, but until 275°C the material retains excellent transparency although it displays negligible PSL. Between 275°C and 277°C, the hexagonal phase converts to the orthorhombic phase, the transparency abruptly decreases, and the PSL rises to a value of around 13% of that found for the commercial storage phosphor BaFBr:Eu. For a slightly higher temperature of 280°C, new phases appear which correspond to the onset of bulk crystallization, and at 283°C the relative PSL rises to 33%, while the transparency falls further. The trade-off between optical transparency and PSL over this narrow temperature window for X-ray imaging plate applications is briefly discussed.

We found a signi4cant PSL e6ect in Eu 2+ -doped 8uorozirconate glasses (ZBLAN) which were additionally doped with Br − or Cl − ions. The PSL is attributed to the characteristic emission of Eu 2+ present in nano-crystallites of BaBr2 or BaCl2, which form in the glass upon annealing. The metastable hexagonal form of BaX2 (X = Br; Cl) is always formed 4rst before it is converted into the stable orthorhombic form. The particle size increases upon annealing and so does the PSL e?ciency of the glass ceramic. However, there is a saturation of the PSL e?ciency, which is for Br − doping about 9% and for Cl − -doping about 80% of the Eu-doped BaFBr standard. The particle size was determined by transmission electron microscopy (TEM). The TEM results show a clear tendency for bigger particles for longer annealing at the expense of its number. The particle size for the most e?cient phosphor is about 100 nm. c

The development of transparent glass ceramics as X-ray storage phosphors and their advantages over their crystalline counterparts are briefly reviewed. Measurements of conversion efficiency, stimulation efficiency, storage times, and optical transparency are reported for the particular case of europium-doped fluorobromozirconate glass, in which rubidium and lithium replace the usual sodium component fraction. Annealing at 280 °C converts the as-prepared glass into a glass–ceramic which contains Rb2BaBr4 and RbBa2Br5 nano- and micro-crystallites. Only the RbBa2Br5 structure shows significant photo-stimulated luminescence after X-irradiation, and the maximum storage phosphor efficiency is 8% of that for the standard commercial storage phosphor BaFBr:Eu.

A new fluorozirconate glass-ceramic has been discovered that displays an X-ray storage phosphor effect with an efficiency of up to 8% of that observed in the established crystalline storage phosphor, BaFBr:Eu 2+ . The glass-ceramic is based on the well-known ZBLAN20 formulation, but the replacement of Na by Rb and Li, partial substitution of F by Br, as well as doping with Eu 2+ , results in the formation of RbBa 2 Br 5 :Eu 2+ microcrystallites. X-ray diffraction, photostimulated luminescence and EPR measurements on the as-made glass and the annealed glass-ceramic show that the X-ray storage phosphor effect arises from the RbBa 2 Br 5 :Eu 2+ microcrystallites.

Calculations of the optical extinction coefficient for spherical copper-coated dielectric particles in fluorozirconate glass are presented. As the coating thickness is reduced, the plasma resonance wavelength shifts from ≈600 nm in the visible region for thick copper coatings towards the infrared, and traverses the telecommunications windows. Such composite particles, with the appropriate coating thickness, can have a much larger effect on the extinction in the near infrared for a given volume of copper than a solid copper particle.

Optical extinction spectra of CuCl particles in a fluorozirconate glass whose composition is close to that of ZBLAN20 (53% ZrF4, 20% BaF2, 4% LaF3, 3% AlF3, and 20% NaF) are reported. Spectra show a sharp but structured band at 375 nm at room temperature which is resolved into two lines at 378 and 386 nm at 15 K. These two lines are attributed to the free exciton states Z1,2, Z3 of CuCl. Spectra are compared with calculations of optical extinction efficiency of spherical CuCl particles, based on Mie scattering theory. Calculations show that the shape of extinction spectra depends markedly on particle radius for radii above about 20 nm, and that the shape may thus be used to estimate the mean particle size.

By comparing models of market-based allocation with state-controlled national health care systems, it will be suggested that the way in which different communicaties deal with the allocation of health care is central to their expression of what might be called a moral self-understanding. That is to say that the provision of health care may be expected to be a focus of communal debate, not simply about morally acceptable and unacceptable actions, but also about the community’s understanding of what it is that makes for a worthwhile and morally defensible human life. This moral self-understanding is seen to be entwined with the different concepts of ‘health’ that are implicit in different systems of allocation. In conclusion, it will be suggested that decisions concerning health care allocation must be made in response to a continuing, public and open debate about that health and health care mean to a particular community.

Following extended thermal processing under reducing conditions, fluoride glasses with a composition close to the standard 53% ZrF 4 -20% BaF 2 -4% LaF 3 -3% AlF 3 -20% NaF (ZBLAN) formulation scatter red light in a band centred at around 600 nm, together with an associated extinction band centred at around 570 nm. Some samples show a dichroic effect of appearing red in back-scattered light but blue in transmitted light. The spectra are attributed to a dilute colloidal precipitate of copper, present as a residual impurity in the starting material with a concentration of around 1 ppm by volume. Calculations of the extinction and scattering spectra for copper colloidal particles show that the light scattering efficiency peaks at around 600 nm, but is insignificant compared with absorption for particle radii less than about 30 nm. For particle radii between about 30 and 50 nm, the scattering dominates the beam-particle interaction and is still peaked in the red region. For larger radii, the peak in the scattering efficiency becomes invariant and broadens. Fittings based on the calculations suggest that the copper particles responsible for the observed spectra in ZBLAN glass have radii in the range of 16 to 45 nm.

The possibility of using the combination of a computed radiography (storage phosphor) cassette and a semiprofessional grade digital camera for medical or dental radiography is investigated. We compare the performance of (i) a Canon 5D Mk II single lens reflex camera with f1.4 lens and full-frame CMOS array sensor and (ii) a cooled CCD-based camera with a 1/3 frame sensor and the same lens system. Both systems are tested with 240 x 180 mm cassettes which are based on either powdered europium-doped barium fluoride bromide or needle structure europium-doped cesium bromide. The modulation transfer function for both systems has been determined and falls to a value of 0.2 at around 2 lp/mm, and is limited by light scattering of the emitted light from the storage phosphor rather than the optics or sensor pixelation. The modulation transfer function for the CsBr:Eu2+ plate is bimodal, with a high frequency wing which is attributed to the light-guiding behaviour of the needle structure. The detective quantum efficiency has been determined using a radioisotope source and is comparatively low at 0.017 for the CMOS camera and 0.006 for the CCD camera, attributed to the poor light harvesting by the lens. The primary advantages of the method are portability, robustness, digital imaging and low cost; the limitations are the low detective quantum efficiency and hence signal-to-noise ratio for medical doses, and restricted range of plate sizes. Representative images taken with medical doses are shown and illustrate the potential use for portable basic radiography.

There is much interest in various glass-ceramics doped with rare-earth (RE) metals for x-ray storage phosphor and/or x-ray scintillator applications for potential use in high resolution x-ray imaging. The phosphor and scintillator properties of these glass ceramics depend on the formation of RE embedded nanocrystals in their structure. The heat treatment and annealing of the starting RE-doped glasses is critically important to the formation and control of the glass ceramic nanocrystals. We have studied the thermal and photoluminescence properties of Sm-doped fluorochlorozirconate glass ceramics. We selected useful host compositions and appropriate heat treatment and annealing procedures needed to grow the required RE-doped nanocrystals in a glass matrix for sensor applications.

The wide adoption of service orientation and the growing complexity of service-oriented applications presents new challenges in configuring and tuning these applications, both at deployment time and at run time. This paper describes our simulation-based approach to addressing this problem. We have developed a general SOA simulation framework, which includes a tool for automatically generating significant portions of the simulator based on the WSDLs of the web services. Our methodology stipulates the systematic exploration of varying SOA deployment configurations in order to collect behavioral profiles. One can use these to examine the trade-offs between configuration cost and performance, ultimately identifying a cost-effective configuration that complies with a Service Level Agreement. The results can also used to identify configurations that allow for more accurate load-balancing and thus better overall performance.We evaluated our approach on a service-oriented text analysis toolkit. We show that our simulation results, produced by automatically generated code with minor manual changes, match real-world response-time metrics. Given these promising early results we describe future uses of our methodology.

A novel apparatus for obtaining thermoluminescence glow curves is described. Two standard PT100 precision resistors, which have a well-known dependence of resistance on temperature, are connected back to back to provide a sensing and heating element. The resulting hot finger has very low thermal mass, is nonreactive, and is inexpensive. With dry nitrogen gas-flow cooling, an operational range of -50 to 450 degrees C is achievable. A tailored control circuit which is easily calibrated drives the heating element, and temperature ramps are implemented in software. The simple design permits the use of modularly interchangeable hot fingers for rapid measurement of many samples.

We have investigated X-ray induced radioluminescence (XL) properties of Sm-doped fluorochlorozirconate (FCZ) glasses and glass-ceramics. The FCZ glass is a modified ZBLAN glass which shows a very high optical transmission over a wide spectral range. The glass matrix includes Sm3+-doped nanocrystals of BaCl2 after heat-treatment at temperatures above 250 °C. The glass-ceramic emits red light under UV and X-ray exposure. Since conventional Si-based photodetectors, e.g., CCDs, have the highest quantum efficiency to red light in general, the Sm-doped FCZ glass-ceramic plate can be a good candidate as a scintillator material for indirect radiation detection. Moreover, a very broad emission is present in the glass-ceramic around 300–500 nm, which is attributed to a self-trapped exciton (STE) emissions. The temperature dependence of X-ray induced luminescence and photoluminescence are very similar. The XL light yield is linearly proportional to the X-ray exposure rate for rates higher than 20 mR/s. For low exposure rates, emissions by Sm2+ are more sensitive than others, leading to a nonlinear response.

Previous work has demonstrated that fluorophosphate (FP) glasses doped with trivalent samarium (Sm3+) can be used as a dosimetric detector in microbeam radiation therapy (MRT) to measure high radiation doses and large dose variations with a resolution in the micrometer range. The present work addresses the use of intense optical radiation at 405 nm to erase the recorded dose information in Sm3+-doped FP glass plates and examines the underlying physics. We have evaluated both the conversion and optical erasure of Sm3+-doped FP glasses using synchrotron-generated high-dose x-rays at the Canadian Light Source. The Sm-ion valency conversion is accompanied by the appearance of x-ray induced optical absorbance due to the trapping of holes and electrons into phosphorus-oxygen hole (POHC) and electron (POEC) capture centers. Nearly complete Sm2+ to Sm3+ reconversion (erasure) may be achieved by intense optical illumination. Combined analysis of absorbance and electron spin resonance measurements indicates that the optical illumination causes partial disappearance of the POHC and the appearance of new POEC. The suggested model for the observed phenomena is based on the release of electrons during the Sm2+ to Sm3+ reconversion process, the capture of these electrons by POHC (and hence their disappearance), or by PO groups, with the appearance of new and/or additional POEC. Optical erasure may be used as a practical means to erase the recorded data and permits the reuse of these Sm-doped FP glasses in monitoring dose in MRT.

The problem of public consultation over the allocation of health care resources is addressed by considering the role that quality of life measures, such as QALYs and the Nottingham Health Profile, could play. Such measures are typically grounded in social surveys, and as such may reflect public preferences for health care priorities. Using Charles Taylor's concepts of “weak” and “strong” evaluation, it is suggested that current quality of life measures are inadequate, insofar as they typically presuppose that survey respondents are mere “weak evaluators”, who express only inarticulate preferences. Respondents may, conversely, be understood as strong evaluators, with deeper visions of human nature and the good life informing their health preferences. Space is then created for such respondents to be asked to defend their preferences, and so be encouraged to reflect critically and publicly on the beliefs and prejudices that ground their view of health care priorities.

We have performed numerical simulations to determine the modulation transfer function for glass ceramic x-ray imaging plates where the image readout is by a scanned laser beam. We focus, in particular, on the role of the effective scattering length in determining the width of the modulation transfer function, covering a range of scattering lengths describing very opaque to very transparent glass ceramics. We find that the shape of the modulation transfer function is, in general, bimodal, with a broad contribution from the laser beam width, and superimposed a narrow one from scattering. The overall width of the modulation transfer function reaches a minimum when the scattering length is comparable with the beam width, and so scattering lengths either much greater or less than the beam width, corresponding to either strongly scattering or highly transparent glass ceramics, give the best expected spatial resolution. However, for a practical range of scattering parameters, transparent glass ceramics are predi...

The effects of ultraviolet (UV) irradiation on the optical absorption, optically stimulated luminescence (OSL), and thermoluminescence (TL) properties of RbCdF3:Mn2+ are reported. There is a UV induced optical absorption at ∼4 eV, together with OSL and TL that are attributed to a distribution of carrier traps, as well as isolated or disconnected traps. We show that the time-integrated OSL for samples with different Mn2+ concentrations is correlated with the UV-induced change in the absorption coefficient, which we attribute to a higher trap concentration in samples with high Mn2+ concentrations. The UV-induced changes in the optical properties can be completely bleached, which leads to the possibility of holographic storage. We show that stable and rewritable thick Bragg gratings can be made in RbCdF3:Mn2+ single crystals after UV irradiation at 254 nm where the gratings were made by two beam interference at 364 nm.

Optical absorption and optically stimulated luminescence measurements have been made on RbCdF3:Mn2+. We show that there is an ultraviolet (UV) response that covers the UV spectrum and hence this compound is applicable for passive UV detection and dosimetry. There is a fast UV-A and UV-B stimulated luminescence decay when compared with the bleaching of the deep UV induced optical absorption that can be explained in terms of a distribution of carrier traps with different detrapping rates.

The light scattering from particles in a glass ceramic is calculated for a particle model comprising a crystalline core and a surrounding shell, created by nucleation and diffusive processes from the original homogeneous glass, with diffusing atoms limited to the core-shell volume. The scatterings from core and shell are found to cancel in first order for small particles within the approximations of the Rayleigh-Debye theory. The residual scattering varies as the inverse eighth power of wavelength and is most pronounced in the backscatter geometry.