The aim of the study was to upgrade the Horia Hulubei National Institute for Physics and Nuclear Engineering existing facility - a 3 MV TandetronTM accelerator - to be used in radiobiology experiments. Irradiations were performed with 1.95 MeV protons (beam with uniform distribution over a 30 mm2). Particle fluence was determined with plastic track detectors and live monitored using Rutherford Backscattering Spectrometry technique. Absolute and relative dose (Advanced Markus ion chamber) and the lateral quality of the irradiation spot (radiochromic film) were measured. The dosimetric measurements were confirmed by Geant4 simulations of the dose averaged Linear Energy Transfer, the Bragg peak profile and the beam lateral energy distribution. A complete setup for exposing in vitro cell cultures to the particle beams was constructed from scratch. Preliminary data of survival rate of V79 fibroblast cells are reported. The obtained results are similarly with data reported using other proton beam facilities.

At the new ultrahigh power laser facility ELI NP, experiments on the interaction of high power lasers and matter will be conducted. These experiments are expected to produce beams of highly energetic particles resulting in secondary radiation fields which will be highly complex and rather difficult to measure given their specifics (extremely short bursts, with time widths in the range of nanoseconds). The ELIFLUKA project was started to assess the doses in the areas surrounding the experimental halls, to evaluate the efficiency of the existing shielding solutions, to propose, if necessary, their optimization, and give optimal ways to monitor the radiation fields that might affect the facility personnel. The present paper is focused on the results concerning the composition and the spectra of the secondary radiation fields inside the E’ experimental hall. A complex FLUKA geometry of the El area was built according to the real design of the experimental hall. With FLUKA we calculated the particle fluencies, the spatial distribution and spectra of each component of the radiation field, corresponding to two limit source terms, characterised by a thermal energy distribution with 40 MeV average and 250 MeV cut-off, and a second one with a flat energy distribution with 500 MeV average and 50 MeV FWHM. The FLUKA code was used to calculate all particle fluence spatial distribution inside the experimental hall, as well as the fluences and spectra for the main components of secondary radiation fields. These results can be used to design various experimental setups at E1 in such a way that the instruments would be positioned without risking significant activation and/or radiation damage and they provide a source term for the shielding calculations using the classical methods, as usually requested by the regulatory authorities.

In all the future applications of the laser accelerated beams (as generated in the ELI and CETAL projects) in-beam dose measurements will be needed. The gold standard in dose measurement remain the ion chambers, but for the beams we intend to measure they do present some limitations given be the large number of corrections to be applied in order to calculate a correct dose from the measured charge. The ELIDOSE project is addressing these problems by proposing an array detector that would allow the simultaneous measurement of the recombination and polarity corrections, as well as of the dose – the QUADRO-fm (Quad Detector for RecOmbination factor measurement). The prototype detector consists of 4 identical ion chambers mounted together in a PMMA frame and the project analyses its response to various charged particle beams and the reciprocal influences of the chambers on each other. This reciprocal influences of the four chambers have been studied in well characterised therapy electron beams and conclusions regarding further developments have been drawn. The paper presents the characterisation of the proton and electron beams used in the experiment, as well as the dose measurements in the 5 MeV electron beams generated by a Siemens radiotherapy LINAC and the comparison with the FLUKA based simulations.

In this paper we present a study of the crosstalk of the individual measuring volumes in a 2D ion chamber array (QUADRO-fm detector) under proton irradiation. This is the follow-up of the similar study performed for this detector in the case of electron beams. The goal of the paper is to assess the applicability of the proposed array for measurements in charged particle beams generated by ultra-high-power laser - target interactions. Using FLUKA calculations and similar geometry conditions as for the electrons, we obtained relative dose deviation values in a 250 MeV monoenergetic proton beam. The results show low values for this quantity, in the case of the selected parameters. We can conclude that the QUADRO-fm detector can be successfully used in any type of charged particle beams generated at ELI-NP and that the calibration of the array can be performed relative to the central dose.

The high levels of ionizing radiation expected at most of the experimental areas of the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility in Bucharest are challenging from a radiation protection point of view. FLUKA Monte Carlo code is a widely used tool allowing to estimate dose contributions of the complex radiation fields and the transport of the radiation through the bulk shielding. In this paper we present the results of a shielding study for the experimental area E1, the site of the laser driven nuclear physics experiments. Updated source terms were used and ambient dose equivalent rates were calculated to check the compliance with the design target dose values and to identify critical dose locations. To reduce radiation levels for neighbouring areas below the required limits, an optimized beam dump and local shielding were proposed.

FLUKA simulations were used to design a dosimetry monitoring system for the typical electron acceleration experiments in the E6 area of the ELI-NP building. The FLUKA geometry of the E6 experimental area was built by using data extracted from the latest available version of the corresponding Catia file, including all the building and beamline transport elements. Based on that geometry we calculated H*(10) in a Cartesian binning over E6 and neighbouring areas for the worst case scenario: a 38 GeV Gaussian electron source term. The fluence rates of the secondary prompt radiation field components were mapped throughout the E6 experimental area. The results were used to determine the most important contributor to the dose and the areas with the highest exposure, as well as the positioning of the detectors for radiation monitoring. We propose solutions for some practical issues: proper choice of the detector type and proper detector positioning in accordance with the characteristics of the radiation field (dose range, field components, energy ranges).

In-beam dose measurements are paramount for any application seeking to harness the effects of the radiation beam, so all the future applications of the laser accelerated beams (as generated in the ELI and CETAL projects) will need such measurements. With a very long history in measuring doses in charged particle beams, the medical and industrial applications setup a number of methods that could be also used for the dosimetry of the beams generated by laser pulses. Dose measurements rely heavily on what is seen as the gold standard in dose measurement: the ion chambers. Ion chambers have both limitations and advantages, and in our case the disadvantage could be the large number of corrections to be applied in order to calculate a correct dose from the measured charge. The ELIDOSE project tries to address these problems by proposing an array detector that would allow the simultaneous measurement of the recombination and polarity corrections, and of the dose. The detector consists of four identical ion chambers mounted together in a PMMA frame and the project will analyze its response to various charged particle beams and the reciprocal influences of the chambers on each other. These reciprocal influences of the four chambers are studied through the FLUKA modeling of the detector and, in order to hone the simulations of the detectors, we initially compared the results of the measurements performed with an Advanced Markus (TM) chamber in the proton beam delivered at the 3-MV Tandetron (TM) from IFIN-HH. The paper presents the results of these initial measurements and how these results will be used to modify the simulation parameters.

In this paper we present a preliminary study of the reciprocal influences (crosstalk) of the individual measuring volumes in a 2D ion chamber array. The array was designed to be used in the charged particle beams generated by ultra-high-power laser - target interactions. FLUKA Monte Carlo code simulations were performed to obtain dose values in a single detector placed in the geometrical center and in the individual measuring volumes of the array. A quantitative measure of crosstalk was obtained by calculating relative dose deviation values for several divergence angles of a 6 MeV spatially extended electron source and for a range of external distance values between individual measuring volumes. The results show that the relative dose deviation values are very low. No functional dependency on the considerend parameters was found. This indicates that the array can be successfully used in measurements of the radiadion generated by the ultra-high power laser pulses and that it can be calibrated relative to the central dose.

Ultra-high intensity lasers in use are connected with ionizing radiation sources that raise a real concern in relation to installations, personnel, population and environment protection. The shielding of target areas in these facilities has to be evaluated from the conceptual stage of the building design. The sizing of the protective concrete walls was determined using computer codes such as Fluka. For the experiments to be carried out in the facility of the Center for Advanced Laser Technologies (CETAL), both proton beams with the energy of 100 MeV and electron beams with 300 MeV energy were considered to calculate the dimensions of structural shielding and to establish technical solutions fulfilling the radiation protection constraints imposed by the National Commission for Nuclear Activities Control.

The Optical Coherence Tomography (OCT) is an emerging imaging technique with applications in medicine and biomedical optics. OCT is capable of analyzing internal localized microstructures and obtaining high-resolution cross-sectional images by backscattered light echo analyze. With resolutions of 1-15 mu m, one or two orders of magnitude finer than conventional ultrasound, the OCT is improving the small body imaging techniques. The OCT is mostly a near infrared based analysis technique. The design of OCT systems is based on a Michelson interferometer coupled with a low coherence light source. One arm of the interferometer emits a directed beam scanning the sample. OCT imaging engines usually employ time domain detection using a reference delay arm in order to perform the interferometry. The development of high speed diffraction grating scanners enabled OCT systems to achieve imaging speeds of several thousand axial scans per second and also video rate imaging. A generic OCT system uses a circulator to collect phase interference signals. By subtracting the signals, the desired interference signal adds and excess noise from the light source gets cancelled. This configuration is nominated as dual balanced detection and is used in coherent optical communications systems. Considering its ability to in vivo analyze and its capacity to obtaining cross-sectional images, the OCT system can be implemented as a tool used to improve the surgical gesture during tumor removal surgeries. In order to obtain the best results, the OCT needs to be improved with a simple spectroscopic device.

A secondary standard chamber for measuring the conventionally true value of the personal dose equivalent, Hp(10), was developed by Arckerhold et al. at Physikalisch Technische Bundesanstalt (PTB). This type of chamber together with a secondary standard ionization chamber for direct measurement of ambient dose equivalent, H*(10), both outfitting the Secondary Standard Dosimetry Laboratory (SSDL), were used for area monitoring at the NILPRP 7 MeV Linear Accelerator. Measurement results, for both ICRU operational quantities, are presented in this paper. (C) 2010 Elsevier Ltd. All rights reserved.

Soon after the Chernobyl accident, the radioactive cloud, carrying the nuclides released into the atmosphere, reached Romania and, due to the rainy weather, an important fallout occurred over the Romanian territory. The most important contaminants for Romania were I, Cs, Cs and Sr. As in many other countries, in the first days, I had the main contribution to the irradiation dose released to the population. After its decay, and the decay of the other short-lived radionuclides, Cs and Sr remained the most important contaminants. The principal route of intake for these two radionuclides is considered to be the ingestion of contaminated foods. To assess the radioactive burden of foods, a long term, large scale survey was initiated at the National Institute of Hygiene and Public Health (INISP). These results were then used to asses the doses committed due to cesium and strontium intake and the excedentary cancer risk for the population from Bucharest area [1].

The fading of the thermoluminescent phosphors used as dosemeters is of great importance when it comes to calibrating a dosimetric system. The results of a series of experiments performed in order to determine some fading characteristics of TLD-100 (Harshaw Chemical Co.) are presented. The experiment was performed using two batches of dosemeters that were irradiated with X rays simultaneously and with the same dose. One of the two batches was used to determine the thermal fading at room temperature, and the other one to determine the combined optical and thermal fading. The results indicated that, after the low temperature peaks had faded out, the response of the dosemeters exposed to light became quite stable, with a very low fading. The signal of the dosemeters kept away from light continued to fade down to a lower level than the signal of the dosemeters exposed to light. The results of other experiments involving UV irradiation after the irradiation with X rays, and their implications for the calibration of personal dosemeters are also presented.