http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Proton Radiography and Fast Electron Propogation Through Cyliderically Compressed Targets
R. Jafer,L. Volpe,D. Batani,M. Koenig,S. Baton,E. Brambrink,F. Perez,K. Lancaster,M. Galimberti,R. Heathcote,M. Tolley,Ch. Spindloe,P. Koester,L. Labate,L. Gizzi,C. Benedetti,A. Sgattoni,M. Richetta,J 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.21
The paper describes the key points contained in the short term HiPER (High Power laser Energy Research) experimental road map, as well as the results of two phases of the experiment performed in “HiPER dedicated time slots. Experimental and theoretical results of relativistic electron transport in cylindrically compressed matter are presented. This experiment was achieved at the VULCAN laser facility (UK) by using four long pulse beams (∽4 × 50 J, 1 ns, at 0.53 µm) to compress a hollow plastic cylinder filled with plastic foam of three different densities (0.1, 0.3, and 1 g cm−3). In the first phase of the experiment, protons accelerated by a picosecond laser pulse were used to radiograph a cylinder filled with 0.1 g/cc foam. Point projection proton backlighting was used to measure the degree of compression as well as the stagnation time. Results were compared to those from hard X-ray radiography. Finally, Monte Carlo simulations of proton propagation in cold and compressed targets allowed a detailed comparison with 2D numerical hydro simulations. 2D simulations predict a density of 2-5 g cm−3 and a plasma temperature up to 100 eV at maximum compression. In the second phase of the experiment, a short pulse (10 ps, 160 J) beam generated fast electrons that propagated through the compressed matter by irradiating a nickel foil at an intensity of 5 × 1018 Wcm−2. X-ray spectrometer and imagers were implemented in order to estimate the compressed plasma conditions and to infer the hot electron characteristics. Results are discussed and compared with simulations.
Proton Radiography for Inertial Confinement Fusion
L. Volpe,D. Batani,S. Baton,F. Perez,M. Koenig,Ph. Nicolai,B. Vauzour,J. J. Santos 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.51
Generation of high intensity and well collimated multi energetic proton beams from laser-matter interaction extend the possibility to use protons as a diagnostic to image imploding target in Inertial Confinement Fusion experiments in the framework of experimental road map of Hiper project (the European High Power laser Energy Research facility Project). Due to the very large mass densities reached during implosion processes, protons travelling through the target undergo a very large number of collisions which deviate protons from their original trajectory reducing Proton Radiography resolution below our expectations. Here We present a simple analytical model to study the Proton Radiography performance as a function of the main experimental parameters such as proton beam energy and target areal density. This approach leads to define two different criteria for PR resolution (called "strong" and "weak" condition) describing different experimental conditions.Finally numerical simulations using both Hydrodynamic and Monte Carlo codes are presented to validate analytical predictions.
Spectral tomographic analysis of Bremsstrahlung X-rays generated in a laser-produced plasma
Rhee, Y.J.,Nam, S.M.,Peebles, J.,Sawada, H.,Wei, M.,Vaisseau, X.,Sasaki, T.,Giuffrida, L.,Hulin, S.,Vauzour, B.,Santos, J.J.,Batani, D.,McLean, H.S.,Patel, P.K.,Li, Y.T.,Yuan, D.W.,Zhang, K.,Zhong, J. Cambridge University Press 2016 Laser and particle beams Vol.34 No.4
<B>Abstract</B><P>A new approach is proposed to analyze Bremsstrahlung X-rays that are emitted from laser-produced plasmas (LPP) and are measured by a stack type spectrometer. This new method is based on a spectral tomographic reconstruction concept with the variational principle for optimization, without referring to the electron energy distribution of a plasma. This approach is applied to the analysis of some experimental data obtained at a few major laser facilities to demonstrate the applicability of the method. Slope temperatures of X-rays from LPP are determined with a two-temperature model, showing different spectral characteristics of X-rays depending on laser properties used in the experiments.</P>