Novel X-Ray Source Using Rear Side X-Ray Emission from the Foil Target

1996 ◽  
Vol 76 (2) ◽  
pp. 232-234
Author(s):  
H. Hirose ◽  
K. Ando ◽  
K. Miyazawa ◽  
T. Hara ◽  
K. Kodate ◽  
...  
Keyword(s):  
X Ray ◽  
1992 ◽  
Vol 10 (4) ◽  
pp. 743-751 ◽  
Author(s):  
M. Chvojka ◽  
B. Králiková ◽  
E. Krouský ◽  
L. Láska ◽  
K. Maŝek ◽  
...  

The first harmonics beam generated by an iodine laser system was focused by an f/2 optics on an Al foil target. The X-ray output from the laser plasma both in the line and broad-band spectra was registered over an interval around the “ideal” focus. It was found that the maximum X-ray power is not obtained in the focus itself but for a somewhat larger focal spot outside the focus. To explain this phenomena, temperature and density measurements were in addition made. The plasma temperature evaluated from both the line (He-like Al XII resonant line and j, k, l satellites) and broad-band spectra (two foil method) was also measured and found to be largely constant in the vicinity of the focus. The line and broad-band temperatures differ, the broad-band temperature being about 25% higher. The electron density was equally determined using an intercombination line.


Nukleonika ◽  
2015 ◽  
Vol 60 (2) ◽  
pp. 233-237 ◽  
Author(s):  
Vojtěch Horný ◽  
Ondřej Klimo

Abstract Fast electrons created as a result of the laser beam interaction with a solid target penetrate into the target material and initialize processes leading to the generation of the characteristic X-ray K-α radiation. Due to the strong electric field induced at the rear side of a thin target the transmitted electrons are redirected back into the target. These refluxing electrons increase the K-α radiation yield, as well as the duration of the X-ray pulse and the size of the radiation emitting area. A model describing the electron refluxing was verified via particle-in-cell simulations for non-relativistic electron energies. Using this model it was confirmed that the effect of the electron refluxing on the generated X-ray radiation depends on the target thickness and the target material. A considarable increase of the number of the emitted K-α photons is observed especially for thin targets made of low-Z materials, and for higher hot electron temperatures.


1991 ◽  
Vol 9 (2) ◽  
pp. 527-540 ◽  
Author(s):  
D. Babonneau ◽  
J. L. Bocher ◽  
C. Bayer ◽  
A. Decoster ◽  
D. Juraszek ◽  
...  

We present results of X-ray emission by the rear side of gold thin targets irradiated by the Phebus laser at λ = 0.35 μm, τ = 0.7 and 1.3 ns, and EL = 1.5 kJ. A streak camera coupled with a transmission grating gave the time-resolved X-ray emission of the rear side. Also, a streak camera coupled with a slit allowed us to obtain information about the space and time evolution of the plasma. Some other diagnostics gave information about the energy balance and the X-ray conversion efficiency. The results are in good agreement with previous ones obtained with the Octal laser, particularly on optimum thicknesses for X-ray conversion efficiencies. Values of the thermal flux limiter are deduced. Simulations with FCI 1 code with multigroup radiative transfer and non-LTE ionization reproduce the experimental results only about some points. A number of reasons, such as 2-D effects and problems of opacity, are invoked.


2010 ◽  
Vol 59 (7) ◽  
pp. 4767
Author(s):  
Wang Chen ◽  
Zheng Wu-Di ◽  
Fang Zhi-Heng ◽  
Sun Jin-Ren ◽  
Wang Wei ◽  
...  

1989 ◽  
Vol 7 (3) ◽  
pp. 495-504 ◽  
Author(s):  
K. A. Tanaka ◽  
Y. Kato ◽  
S. Nakai ◽  
H. Shiraga ◽  
T. Yabe ◽  
...  

Emissions from the rear side of the targets were temporally resolved by irradiating an ultraviolet (UV) laser on Al and Au thin targets. A difference was clearly observed between the above two targets. Given the fact that absorbed laser energy is converted with a very high efficiency to soft x-rays in a high Z plasma, a characteristic emission peak only observed for Au targets was attributed to the effect of soft x-ray energy transport. The ablation pressures estimated from the emissions indicate that the pressure scaling for Au is close to the one by x-ray radiation rather than by a UV laser. With soft x-ray irradiation, energy transport in A1 foils was also studied. An ablation pressure was estimated by the shock speed.


1996 ◽  
Vol 49 (10) ◽  
pp. 1067 ◽  
Author(s):  
JM Harrowfield ◽  
H Miyamae ◽  
BW Skelton ◽  
AA Soudi ◽  
AH White

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for 1 : 1 adducts of (7R*,14R*)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (' tet -b') with a variety of lead(II) salts. [( tet -b)PbCl2] is monoclinic, P 21/c, a 7.183(3), b 12.425(2), c 24.418(2) Ǻ, β 95.32(3)°, Z = 4; conventional R on |F| was 0.044 for 3188 independent, 'observed' (I > 3σ(I)) reflections. [( tet -b)PbI2] is monoclinic, P 21/c, a 19.920(5), b 7.772(5), c 15.605(6) Ǻ, β 108.39(2)°, Z = 4; R 0.051 for No 2507. [( tet -b) Pb (NCS)2] is orthorhombic, P 212121, a 36.99(1), b 8.996(5), c 6.964(3) Ǻ, Z = 4; R 0.043 for No 2100. All are discrete mononuclear [( tet -b)PbX2] entities in which the macrocyclic N4 ligand occupies one 'face' of the N4PbX2 coordination sphere, the thiocyanate ligands being N-bonded, with Pb -N-C angles of 116(2) and 118(1)°; interesting hydrogen-bonding interactions are found, columns of molecules being formed by way of hydrogen bonding between the coordinated (pseudo-)halides and the NH hydrogen atoms which project to the 'rear' face of the ligand of the next molecule, opposite the metal. In contrast to these, the bromide analogue, monoclinic, P21, a 9.342(3), b 12.720(5), c 18.845(5) Ǻ, β 103.17(2)°, Z = 4, R 0.035 for No 3593, is best formulated as [( tet -b) PbBr ] Br, one only of the bromide entities being bound to the lead, the other being fully dissociated by hydrogen bonding/ion pairing to the 'rear' side of adjacent ligands , forming hydrogen-bonded sheets rather than columns. This formulation has been extended to provide a description of an analogous mixed chloride- perchlorate 'double salt', [( tet -b) PbCl ] (ClO4).CH3OH, which is orthorhombic, P 212121, a 19.475(2), b 18.73(1), c 6.820(2) Ǻ, Z = 4, R 0.054 for No 3075. However, another double salt, modelled in refinement as Pb ( tet -b)Cl0.5(ClO4)1.5.H2O, orthorhombic Pnma , a 20.640(5), b 26.16(1), c 8.937(4) Ǻ, Z = 4 dimers , R 0.074 for No 1769, is in this case more appropriately described as [( tet -b) Pb (OClO2O)2Pb( tet -b)] (ClO4) Cl.H2O with perchlorate rather than halide coordinated, and an incipiently dimeric cation, as in the parent [( tet -b) Pb (OClO3)]2 (ClO4)2.2H2O.


2016 ◽  
Vol 23 (1) ◽  
pp. 59-66 ◽  
Author(s):  
D. Spiga ◽  
M. Barbera ◽  
A. Collura ◽  
S. Basso ◽  
R. Candia ◽  
...  

Adjustable mirrors equipped with piezo actuators are commonly used at synchrotron and free-electron laser (FEL) beamlines, in order to optimize their focusing properties and sometimes to shape the intensity distribution of the focal spot with the desired profile. Unlike them, X-ray mirrors for astronomy are much thinner in order to enable nesting and reduce the areal mass, and the application of piezo actuators acting normally to the surface appears much more difficult. There remains the possibility to correct the deformations using thin patches that exert a tangential strain on the rear side of the mirror: some research groups are already at work on this approach. The technique reported here relies on actively integrating thin glass foils with commercial piezoceramic patches, fed by voltages driven by the feedback provided by X-rays, while the tension signals are carried by electrodes on the back of the mirror, obtained by photolithography. Finally, the shape detection and the consequent voltage signal to be provided to the piezoelectric array will be determined by X-ray illumination in an intra-focal setup at the XACT facility. In this work, the manufacturing steps for obtaining a first active mirror prototype are described.


1993 ◽  
Vol 11 (1) ◽  
pp. 109-117 ◽  
Author(s):  
H. Daido ◽  
Y. Kato ◽  
K. Murai ◽  
G. Yuan ◽  
H. Shiraga ◽  
...  

We describe the properties of the exploding foil neon-like germanium soft X-ray lasers having wavelengths of 19–28 nm and gain length product of more than 10. The measured X-ray intensity of lasing lines from an exploding foil target has been explained with the results of the plasma hydrodynamic code from the viewpoint of suitable condition of electron density and temperature for creating population inversion.


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