Consideration on calibration and correction factors of an Hp10 chamber for different radiation qualities and angles of incidence

This paper presents the characterisation performed at IRSN (France) of an H(p)(10) chamber in terms of calibration coefficient and correction factors for the radiation qualities of ISO narrow spectrum series. The chamber response, expressed in H(p)(10) using conversion coefficients h(p)(K)(10; N, alpha) listed in ISO 4037-3 in the energy range from 30 to 1250 keV and for angles of incidence between 0 and 70 degrees, was found to be within approximately 10%. However, for photon energies <30 keV, an overresponse of the chamber that could reach 100% was observed. Nevertheless, this overresponse was reduced to 25% using the conversion coefficients estimated at Physikalisch-Technische Bundesanstalt (PTB). This implies that the X-ray spectra produced by the IRSN X-ray units are very similar to those produced by PTB, both containing a little bit more high-energy photons than the spectra used in ISO 4037-3. The dose rate dependence of the chamber tested by gamma radiation from (60)Co sources was found to be within 2% in the range of 0.3 mSv h(-1) to 1 Sv h(-1). The H(p)(10) chamber can measure directly the conventional true value of H(p)(10) after calibration by a reference laboratory, and can be used for transferring H(p)(10) reference quantities from a reference laboratory.     

X reference radiation qualities produced with tube voltages above 300 kV for the calibration and testing of dosemeters

In the international standard ISO 4037-1, only X reference radiation qualities produced with tube voltages of up to 300 kV and with mean photon energies of lower than 250 keV are defined. Higher energy reference photon fields are given with a mean energy only from 662 keV (S-Cs) upwards. To close this energy gap, four new X radiation qualities, produced with tube voltages of 350 kV and 400 kV, were realised. The filtration of two of these qualities-called N-350 and N-400-was chosen in such a way that they agree with the specifications of the narrow-spectrum series (N-series) defined in ISO 4037-1. The other qualities which have been created-called H-350 and H-400-can be assigned to the high air-kerma rate series (H-series). The fluence spectra of these qualities were measured by using X-ray spectrometry. The values of 23 characteristic parameters were determined and compared with the ISO specifications for X-ray reference fields.     

A legally approved personal dosemeter for photon and beta radiation based on direct ion storage

The novel DIS-1 dosemeter developed by RADOS is based on ionisation chambers with so-called Direct Ion Storage (DIS). The dosemeter can measure Hp(10) and Hp(0.07) of photon and Hp(0.07) of beta irradiation. The characteristics of the commercially available DIS-1 dosemeter were studied at the Paul Scherrer Institute, particularly in respect to the requirements laid down in the Swiss Dosimetry Ordinance. Detailed tests were carried out in terms of linearity, photon and beta responses, angle dependence, long-term stability of the signal, reproducibility and environmental conditions. The DIS-1 dosemeter has been qualified by the authority to conform to the requirements of the Swiss Dosimetry Ordinance for personal photon and beta dosemeters. It is now used as a legally approved personal dosemeter system at PSI.     

Establishment of radiation qualities for mammography according to the IEC 61267 and TRS 457

This article presents the technical conditions necessary to establish appropriate radiation qualities for the calibration of the dosemeters used in the mammography detectors in the Laboratório de Ciências Radiológicas (LCR) from the Universidade do Estado do Rio de Janeiro. Tests were conducted to evaluate the homogeneity of the radiation field, scattering, half-value layers and system stability. The calibration method (substitution) is described in this work. A moderate alteration in filtration makes it possible to maintain the half-value layers within the limits recommended. The results indicate the adequacy of the LCR laboratory for the calibration of the dosemeters in the radiation qualities for mammography with an expanded uncertainty in the best measurement capability of ± 1.8 % (k = 2).     

Performance of simple response method for the establishment and adjustment of calibration intervals

Managing calibration intervals in order to fulfill requirements of quality-oriented organizations is discussed in this paper. In particular, the simple response method is considered. According to this technique, the interval between successive calibrations is adjusted adaptively on the basis of the outcome of the last calibration process. An original analysis is presented about the properties of such calibration interval handling methods. Finally, directions are given on how to tune its parameters optimally, in order to meet desired levels of long-term measurement reliability.     

Principles for the design and calibration of radiation protection dosemeters for operational and protection quantities for eye lens dosimetry

The work package two of the ORAMED project--Collaborative Project (2008-2011) supported by the European Commission within its seventh Framework Programme--is devoted to the study of the eye lens dosimetry. A first approach is to implement the use of H(p)(3) by providing new sets of conversion coefficients and well suited calibration and type test procedures. This approach is presented in other papers in the proceedings of this conference. Taking into account that the eye lens is an organ close to the surface of the body, another approach would be to directly estimate the absorbed dose to the eye lens, D(lens,est) through a special calibration procedure although this quantity is not directly measurable. This paper is a methodological paper that tries to identify the critical aspects of a dosimetry in terms of D(lens).     

球压痕仪机架柔度对硬度的影响分析与标定方法研究

针对Oliver-Pharr法计算压痕硬度的精度受机架柔度影响的问题,该文将微压痕仪简化为弹簧串联模型,基于Oliver-Pharr方法,建立机架柔度对接触深度和压痕硬度误差影响的解析模型。采用有限元仿真分析,获得压痕功比值与压痕深度比值之间的函数关系,建立实际压痕深度与机架柔度无关的压痕参数的解析模型,实现机架柔度的标定。实验表明:该方法能够快速高效地对机架柔度进行标定。     

Sealing Fuji Prescale pressure sensitive film for protection against fluid damage: the effect on its response

Fuji Prescale pressure sensitive film will record pressures as a characteristic pink stain; the optical density response of these stains can be calibrated to allow subsequent conversion into full field pressure data. Due to its ease of use, Fujifilm has been employed extensively within animal joints. For this application, the potential disruption to the stain producing mechanism posed by the presence of joint fluids has led to the widespread use of fluid proof materials, within which the Fujifilm is protected; however, little data have been presented on the effect of protective materials on the subsequent stain response. This paper presents a quantitative assessment of the mean optical density responses of both protected film and a control group of unprotected film; the first group consisted of Fujifilm sealed between two layers of a readily available self-adhesive material, forming sealed packets. The results indicated significant differences between groups (p<0.05); however, the effect of these differences is dependent on the method used to produce pressure data. Qualitative observations indicated that sealing reduced stain uniformity; preliminary qualitative observations regarding data manipulation methods to overcome this phenomenon are presented. Consequently, this work indicates the importance of validating methods for protecting Fuji film from fluid damage and their associated methods of data manipulation.     

Rayleigh-Mie Doppler wind lidar for atmospheric measurements. II. Mie scattering effect, theory, and calibration

A theoretical and experimental study is conducted for the direct-detection Doppler Lidar developed by the Service d'Aéronomie du Centre National de la Recherche Scientifique. Thanks to a specific design, the double-edge technique that applies primarily to Rayleigh scattering can also be employed in presence of aerosols backscatter. We focus on a careful estimate of the particle-induced error on the wind measurements. With a theoretical model for the Fabry-Perot interferometer and two sets of calibration measurements, the true spectral properties of the interferometer and the calibration curves are recovered. Furthermore, the particle-induced error is estimated for varying values of the scattering ratio at 532 nm. When applied to real atmospheric signals, this error is shown to be negligible. A comparison between ancillary data and the wind and backscatter ratio as retrieved from the Doppler lidar signals confirms our estimate.     

压电/磁致伸缩/环氧树脂层合复合材料的磁电效应及其频响特性

磁电复合材料在磁-电能量转换等领域具有重要的潜在应用价值, 研究磁电复合材料在较高频率下的磁电耦合特性对于实际应用具有重要意义。本文中以0-3型的Terfenol-D(Tb_0.30Dy_0.70Fe₂)/环氧树脂复合材料为磁致伸缩层, 以PZT 压电陶瓷为压电层, 制备了三明治结构的层合磁电复合材料。研究了Terfenol-D/环氧树脂复合材料层的磁致伸缩性质, 并对所制备的层合磁电复合材料磁通密度、 介电常数以及磁电电压系数等随频率和偏磁场的变化规律进行了系统研究。结果表明, 由于Terfenol-D/环氧树脂复合材料的引入, 层合磁电复合材料呈现出良好的频率响应特性, 可靠工作范围大大拓宽。层合磁电复合材料具有优良的动态磁电耦合性能, 在优化偏磁场630 Oe和共振频率69.6kHz下的磁电效应高达21.2 V/cmOe。此外, 层合磁电复合材料的磁电效应随偏磁场的变化发生明显变化, 并存在优化偏磁场。对上述现象和结果进行了详细讨论, 并给出了层合磁电复合材料的磁电耦合机制。      

Nanotechnology and its Impact on the German Energy Sector

In regard to finite resources and in view of the global climate change sustainable development in energy supply gains importance. In addition to the improvement of conventional technologies and the use of renewable energies in this context new technologies and innovations get more important. The described work analyses innovative products and processes based on nanotechnology, with respect to the German energy industry.     

Study on the mechanical properties,environmental effect,degradation characteristics and ionizing radiation effect on silk reinforced polypropylene/natural rubber composites

Natural silk fiber (20%) reinforced polypropylene (PP) composites were prepared by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus, impact strength and hardness of the prepared composite were found 54.7 MPa, 1826.2 MPa, 58.3 MPa, 3750.7 MPa, 17.6 kJ/m² and 95 shore A, respectively. To improve the biodegradable character of the composite, natural rubber (NR) was blended (10%, 25%, 50% by weight) with PP. It was found that the mechanical properties of the composite decrease with increasing NR in PP (except IS which increased rather decreasing). Environmental effect on the composite and degradation in various media were investigated in this study. Gamma radiation was used to increase the mechanical properties of the prepared composites. Increase in TS and BS were maximum at 250 krad dose for silk fiber/PP, silk fiber/PP:NR (90:10), silk fiber/PP:NR (75:25) and silk fiber/PP:NR (50:50) composites.     

Influence of thermal treatments on the response of sand radiation detectors for high-dose dosimetry

The dosimetric properties of sand from Brazilian beaches have shown to be useful for high-dose dosimetry. The thermoluminescent (TL) and electron paramagnetic resonance (EPR) techniques were utilised, and the sand samples were recently studied in relation to their main dosimetric properties. The EPR signal at g = 1.999 grows significantly in function of the absorbed dose, and the TL peaks appear at 110 and 170 degrees C. However, these sand samples present a post-irradiation thermal decay at room temperature, which is a problem for dosimetric procedures. In this study, sand samples have been studied in relation to different thermal treatments. Post-irradiation treatments were performed at 50 degrees C up to 230 degrees C.     

Plastic strain localization in periodic materials with wavy brick-and-mortar architectures and its effect on the homogenized response

Biomimetic or bio-inspired microstructures are increasingly being explored as a source of inspiration for material innovation. The goal of this study is to aid future design of biomimetic materials by conducting analysis of material architectures that resemble brick-and-mortar microstructures found in nacre. Specifically, this study explores the thus-far undocumented combined effects of waviness and platelet architecture on composite material ductility under unidirectional loading parallel and perpendicular to the reinforcing platelets. Model material architectures, comprised of discontinuous silicon carbide platelets suspended in aluminum matrix, that mimic nacre’s microstructure were constructed for analysis with the finite-volume direct averaging micromechanics (FVDAM) theory. The silicon carbide platelets play the role of nacre’s load-bearing calcite phase while the aluminum matrix mimics the combined effects of hierarchical load transferring mechanisms and organic protein matrix. The FVDAM simulations indicate that the introduction of waviness leads to an increase in ductility. Just as significant to material performance is the degree of relative shift between wavy rows of discontinuous hard-phase platelets. The effect of shift on ductility was found to be most significant when introduced to a degree that disrupted unit cell symmetry and when applied to configurations with low amplitude-to-wavelength ratios. The differences in the observed homogenized response are rooted in the local microstructure-controlled stress and resulting plastic strain fields that are identified in this investigation.     

Beam-profile modulation of thulium laser radiation applied with multimode fibers and its effect on the threshold fluence to vaporize water

The threshold fluences at which vaporization is initiated at the tip of a multimode fiber that is submerged in water were investigated when free-running and Q-switched thulium laser pulses (lambda = 2.01 mum) were applied with different pulse energies. We focused on the quantification of temporal and spatial fluence modulations of the beam profile at the tip of a 400-mum fiber. The spatial and the temporal fluence peaks over the average fluence were measured to as high as 1.5 and 4 in the Q-switched mode, respectively, and 2.5 and 40 in the free-running mode, respectively. The fluence peaks significantly influence the vaporization process. An increase in the threshold fluence with increasing pulse energy was found for the Q-switched mode, but there was a decrease for the free-running mode. Pressure transients of the order of 1 kbar and temperatures higher than 200 degrees C were calculated for a 30-mJ Q-switched laser pulse at the onset of vaporization. Collecting all the data allowed us to trace the thermodynamic path of rapid heating and vaporization in a phase diagram of water.     

Some remarks on definitions and, in particular, on the definition of the term calibration

Confucius (Analects xiii:3) ‘It is not possible to haveany valid argument until rigorously defined terms are agreed’. In radiation protection dosimetry, we perhaps need to take asthe fundamental sources of our definitions for personal dosimetryand area monitoring, mainly those three committees—theJoint Committee for Guides in Metrology (JCGM), which givesdefinitions for metrology generally; the International Commissionon Radiation Units and Measurements (ICRU), which gives basicphysical quantities and units for ionising radiation; and theInternational Commission on Radiological Protection (ICRP) forquantities considering the health effect of ionising radiation,for example effective dose, equivalent dose and the qualityfactor/linear energy transfer function. The JCGM, chaired by the Director of the BIPM, is formed bythe seven international organisations that had prepared theoriginal versions of the     

Enhancement of the giant magnetoimpedance effect and its magnetic response in ion-irradiated magnetic amorphous ribbons

The influences of N and Xe ion irradiation on the giant magnetoimpedance (GMI) effect and its magnetic response in Co₆₉Fe_4.5Al_1.5Si₁₀B₁₅ amorphous ribbons were systematically investigated. A large enhancement of the GMI effect and its magnetic response were achieved in N and Xe ion-irradiated amorphous ribbons. At a frequency of 3 MHz, the GMI ratio and magnetic response for an N-ion-irradiated amorphous ribbon respectively reached the highest values of 130% and 13%/Oe, while for a non-irradiated amorphous ribbon they were only about 53% and 8%/Oe. The enhancement of the GMI effect and magnetic response in the ion-irradiated amorphous ribbons resulted from the enhancement of the permeability due to rotational magnetization. Our studies indicate that low energy ion irradiation is useful for improving the magnetic softness, GMI and magnetic response of amorphous alloys, which is of practical importance for the development of high-performance magnetic sensors.