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[en] We discuss our experience with PROOF-Lite in a context of ATLAS Collaboration physics analysis of data obtained during the LHC physics run of 2009-2010. In particular we discuss PROOF-Lite performance in virtual and physical machines, its scalability on different types of multi-core processors and effects of multithreading. We will also describe PROOF-Lite performance with Solid State Drives (SSDs).

[en] Purpose: To study a feasibility of micro-dosimetry with high dose-sensitivity and resolution using two-dimensional Raman mapping on the basis of carbon bonds concentration of radiochromic films Methods: Unlaminated EBT3 films with the purpose of maximal Raman data acquisition were irradiated by 6 MV beam from 5 MU to 1000 MU at the reference condition. Each film was irradiated with shielding material of lead blocking on the half of film as well as the jaw open in half for distinct dose contrast. Raman peaks of 2070 cm-1, 2095 cm-1, and 2115 cm-1 were major subjects to study, which are assumed to be the spectroscopy of carbon triple bonds of monomers, carbon double bonds of polymers, and carbon triple bonds of polymers, respectively. Laser exposure for Raman spectroscopy generated peak’s trend due to polymerization by laser output and this trend was utilized to find out basic peaks related to polymerization process. The relative dose contrast in each one film was detected by Raman spectroscopy with the aid of an auto-scanning stage, comparing the dose contrast between non-irradiated area and irradiated area. Raman spatial resolution was enhanced up to 20 micrometers, assuming the spatial uniformity of radio¬active rod-shaped LiPCDA crystals. An optical scanner with 9600 dpi was used to scan the red-channel intensity to read the dose contrast for 5 MU delivered film. Results: The peak intensity for Raman wavenumber of 2070 cm-1 was used for mapping since it reflected the different peak intensities based on polymerization degree by irradiation. Dose contrast from 1000MU to 5 MU was distinguished by Raman mapping analysis, whereas optical intensity of red-channel didn’t show any difference. Conclusion: In consideration of laser effect, the quantitative analysis based on raw data of Raman mapping could provide more statistically reliable dosimetry than point measurements

[en] We discuss our experience with PROOF-Lite in a context of ATLAS Collaboration physics analysis of data obtained during the LHC physics run of 2009-2010. In particular we discuss PROOF-Lite performance in virtual and physical machines, its scalability on different types of multi-core processors and effects of multithreading. We will also describe PROOF-Lite performance with Solid State Drives (SSDs).

[en] Polycrystalline double perovskites A₂FeMoO₆(A=Ca,Sr,Ba) with nanometer-scale grain size have been synthesized using a sol - gel method. The grain size of the samples is controlled within nanometer scale by sintering at different temperatures. The phase purity and the crystal structure of the samples are analyzed by x-ray powder diffraction measurements. The electrotransport and magnetic properties are also measured in this article. In comparison with the large grain samples with micrometer scale, the nanometer-scale grain samples have different magnetic properties, such as lower magnetic transition temperatures and larger magnetoresistance, which can be explained in terms of size effect. [copyright] 2001 American Institute of Physics

[en] The frequency modulation (FM) mode sensor is widely used in the ultra-precision measuring fields since it has the characteristics of high sensitivity, strong ability of anti-jamming and digital output. The multi-period synchronous frequency discrimination circuit is in regular use to demodulate the output signal of the frequency modulation sensor because of its brief structure, low errors, wide linear range, and low drifting etc. In order to improve the accuracy of frequency discrimination, it generally makes the gate time of count long enough. The error of the demodulation becomes larger with the longer count time. Firstly, this paper takes a certain frequency resonant wave, i.e. the measured signal, as the research object in the time domain and constructs a universal transfer function of the multi-period synchronous frequency discrimination in a certain gate time and analyzes the principle and effect on the accuracy of gate effect based on this function. Then, this paper introduces the amplitude-frequency and phase-frequency characteristics of the multi-period synchronous frequency discrimination system according to the quantitative analysis of the gate effect. Finally, the paper presents a real-time compensation method based on the different frequency components. The experimental data shows that the theoretical calculation of the gate effect on accuracy is in agreement with experimental data and the real-time compensation method can eliminate 90% de-modulation error caused by the gate effect

[en] A method for determining the cross section for compound-nucleus formation, σ_CN, in nuclear reactions initiated by protons of energy in the range 20-100 MeV is proposed. The method is based on measuring cross sections for the yield of isotopes maximally remote from the target nucleus. The applicability of the method is illustrated by applying it to the reaction ²⁰⁹Bi(p, xn), which is considered by way of example. Data obtained for the cross section σ_CN are compared with the results of calculations performed on the basis of the intranuclear-cascade model.

[en] Purpose: to overcome the several issues of ultrasound image-guided radiation therapy (US IGRT) such as probe pressure and optical tracking disability by using a patient-specific three-dimensional couplant pad (CP) fabricated by a patient’s skin mold using a 3D printing technique. Methods: A CP was then fabricated by pouring gelatin solution into a fixed-shape container accommodating the patient skin mold fabricated by a 3D printer. A breast phantom was fabricated with the compound of gelatin and agarose and a phantom study was carried out. From four patients who underwent US IGRT, total 486 ultrasound images with and without a CP were acquired before treatment. Effectiveness of the use of the CP was evaluated. Results: The positioning accuracies in the phantom study were 0.9 ± 0.3 mm and 1.3 ± 0.4 mm with and without the CP in 3D vector amplitude, respectively. In the patient study, the use of CP reduced the mean target shift from 4.7 mm to 3.7 mm in 3D vector amplitude and the one standard deviation from 2.2 mm to 1.7 mm. It also improved the image contrast around the treatment target by 10 %. The centroid offset of the target volume affected from the US scanning coverage and the target deformation due to the excessive probe pressure was decreased from 4.4 mm to 2.9 mm due to the use of CP. Its difference among three different users was statistically significant (p=0.020) without the use of CP but not significantly different (p=0.133) with the use of CP. Conclusion: Our patient-specific 3D CP using a mold by 3D printing technique is a promising strategy for improving tracking accuracy, image quality, and inter-observer variation for ultrasound-based image guided radiotherapy. In addition to its conventional advantage of non-invasiveness, US can be more facilitated in radiotherapy by the developed CP.

[en] The persistent photoconductivity (PPC) effect has been observed in trilayered films made of perovskite manganites La_2/3Ca_1/3MnO₃/(La_0.3Nd_0.7)_2.3Ca_1/3MnO₃La_2/3Ca_1/3MnO₃(LNL) induced by He - Ne laser with wavelength of 632.8 nm. According to the result obtained in the thin film of (La_0.3Nd_0.7)_2/3Ca_1/3MnO₃(LNCMO), which the PPC effect is also observed below ∼50 K, the PPC effect observed in trilayered film LNL should originate from the middle layer LNCMO. Compared with the thin film of LNCMO, the PPC effect of the trilayered film LNL appears at ∼86 K, which is higher than that of LNCMO at ∼50 K. The PPC effect of LNL can be quenched on thermal cycling in the vicinity of 98 K, which is also higher than that of LNCMO at ∼77 K. The difference of PPC behavior between the thin films of LNCMO and LNL can be attributed to the variation of cluster-glass state in the trilayered films of LNL caused by the strong coupling of interlayer between the middle layer LNCMO and the top/bottom layers LCMO. [copyright] 2001 American Institute of Physics.

[en] This paper presents high power test results for high temperature superconductor (HTS) filters having six different configurations. The results demonstrate the possibility of realizing narrow band HTS filters that are capable of handling 30--50 W at 77 K. The paper also introduces a procedure for comparing the power handling capability of HTS filters with different RF characteristics. Issues related to thermal design of high power HTS filters are discussed in detail