STUDY OF X-RAY LASER SCHEMES USING NEW EXPERIMENTAL FACILITIES AT THE RUTHERFORD APPLETON LABORATORY

1986 ◽  
Vol 47 (C6) ◽  
pp. C6-71-C6-79 ◽  
Author(s):  
M. H. KEY ◽  
J. E. BOON ◽  
C. BROWN ◽  
C. CHENAIS-POPOVICS ◽  
R. CORBETT ◽  
...  
Keyword(s):  
Rutherford Appleton Laboratory ◽  
X Ray ◽  
Experimental Facilities

scholarly journals X-Ray Imaging Calibration for Fuel-Coolant Interaction Experimental Facilities

2021 ◽  
Vol 253 ◽  
pp. 06005
Author(s):  
Christophe Journeau ◽  
Michael Johnson ◽  
Shifali Singh ◽  
Fréderic Payot ◽  
Ken-ichi Matsuba ◽  
...  
Keyword(s):  
Test Section ◽  
High Speed ◽  
Limit Of Detection ◽  
Image Intensifier ◽  
Precise Determination ◽  
Severe Accident ◽  
X Ray ◽  
X Ray Imaging ◽  
Experimental Facilities ◽  
Lower Limits

During a severe accident in either sodium-cooled or water-cooled nuclear reactors, jets of molten nuclear fuel may impinge on the coolant resulting in fuel-coolant interactions (FCI). Experimental programs are being conducted to study this phenomenology and to support the development of severe accident models. Due to the optical opacity of the test section walls, sodium coolant, and the apparent optical opacity of water in the presence of intense ebullition, high-speed X-ray imaging is the preferred technique for FCI visualization. The configuration of these X-ray imaging systems, whereby the test section is installed between a fan-beam X-ray source and a scintillator-image intensifier projecting an image in the visual spectrum onto a high-speed camera, entails certain imaging artefacts and uncertainties. The X-ray imaging configuration requires precise calibration to enable detailed quantitative characterization of the FCI. To this end, ‘phantom’ models have been fabricated using polyethylene, either steel or hafnia powder, and empty cavities to represent sodium, molten fuel and sodium vapor phases respectively. A checkerboard configuration of the phantom enables calibration and correction for lens distortion artefacts which magnify features towards the edge of the field of view. Polydisperse steel ball configurations enable precise determination of the lower limit of detection and the estimation of parallax errors which introduce uncertainty in an object’s silhouette dimensions. Calibration experiments at the MELT facility determined lower limits of detection in the order of 4 mm for steel spheres, and 1.7-3.75 mm for vapor films around a molten jet.

scholarly journals A review of X-ray laser development at Rutherford Appleton Laboratory

2002 ◽  
Vol 20 (2) ◽  
pp. 201-209 ◽  
Author(s):  
G.J. TALLENTS ◽  
Y. ABOU-ALI ◽  
M. EDWARDS ◽  
R. KING ◽  
G.J. PERT ◽  
...  
Keyword(s):  
Optical Pumping ◽  
Laser Pulses ◽  
Travelling Wave ◽  
Picosecond Pulse ◽  
Speed Of Light ◽  
Rutherford Appleton Laboratory ◽  
Picosecond Pulses ◽  
X Ray ◽  
Laser Development ◽  
Preformed Plasma

Recent experiments undertaken at the Rutherford Appleton Laboratory to produce X-ray lasing over the 5–30 nm wavelength range are reviewed. The efficiency of lasing is optimized when the main pumping pulse interacts with a preformed plasma. Experiments using double 75-ps pulses and picosecond pulses superimposed on 300-ps background pulses are described. The use of travelling wave pumping with the approximately picosecond pulse experiments is necessary as the gain duration becomes comparable to the time for the X-ray laser pulse to propagate along the target length. Results from a model taking account of laser saturation and deviations from the speed of light c of the travelling wave and X-ray laser group velocity are presented. We show that X-ray laser pulses as short as 2–3 ps can be produced with optical pumping pulses of ≈1-ps.

scholarly journals Transpyrenean Encounter on Advanced Materials

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Pierre Saint-Grégoire
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Carbon Nanotubes ◽  
Experimental Methods ◽  
Advanced Materials ◽  
Electron Holography ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Electron ◽  
Experimental Facilities

TEAM1 has taken place in Sete (France) on 4, 5, 6 july 2017. It has gathered a little less than 40 participants who presented communications on various fields of advanced materials, and on experimental facilities or experimental methods, that are briefly summarized in the present volume. Presented abstracts deal with fullerenes, graphene, thin films, oxides, ferroelectrics, pyroelectrics, piezoelectrics, superconductors, nanomaterials, photovoltaics, X-ray diffraction, electron diffraction, electron microscopy, electron holography, carbon nanotubes, nanorods, ZnO.

scholarly journals Recent experiments at the Rutherford Appleton Laboratory to study the laser driven compression of CH shell targets and the effects of increasing aspect ratio

1986 ◽  
Vol 4 (3-4) ◽  
pp. 573-576
Author(s):  
J. Corbett ◽  
C. L. S. Lewis ◽  
E. Robertson ◽  
S. Saadat ◽  
P. F. Cunningham ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Spatial Resolution ◽  
Systematic Study ◽  
Rutherford Appleton Laboratory ◽  
Density Profiles ◽  
X Ray ◽  
Preliminary Results ◽  
Aspect Ratios ◽  
Laser Facility

Recent experiments to study the laser driven compression of CH shell targets and the effects of increasing aspect ratio using x-ray shadowgraph techniques are described. This work has been carried out at the Rutherford Appleton Laboratory's Central Laser Facility with 12 beam, 0·53 μm, 1·0 ns irradiation. X-ray shadowgraphy techniques have been used with a frame time of ∼100ps and spatial resolution of 5 to lOμm to obtain density profiles for the compressed targets. A systematic study of 150–200 μm targets with aspect ratios from ∼7 to ∼20 has been performed. The x-ray shadowgraphy techniques used are described, results in the form of x-radiographs presented and a discussion of preliminary results given.

X-Ray Laser Research at the Rutherford Appleton Laboratory

1987 ◽  
Author(s):  
O. Willi ◽  
D. Bassett ◽  
C. Chenais-Popovics ◽  
R. Corbett ◽  
M. Grande ◽  
...  
Keyword(s):  
Rutherford Appleton Laboratory ◽  
X Ray

Status of soft X-ray laser research at the Rutherford-Appleton laboratory

1988 ◽  
Vol 30 (1) ◽  
pp. 35-44 ◽  
Author(s):  
C L S Lewis ◽  
R Corbett ◽  
D O'Neill ◽  
C Regan ◽  
S Saadat ◽  
...  
Keyword(s):  
Rutherford Appleton Laboratory ◽  
X Ray

scholarly journals I. The behaviour of single crystals of aluminium under static and repeated stresses

1927 ◽  
Vol 226 (636-646) ◽  
pp. 1-30 ◽  
Keyword(s):  
Single Crystals ◽  
National Physical Laboratory ◽  
Micro Structure ◽  
Important Conclusion ◽  
X Ray ◽  
Slip Bands ◽  
Physical Laboratory ◽  
Slip Planes ◽  
Experimental Facilities ◽  
Crystalline Aggregates

In a previous paper were recorded the results of an investigation into the effects of repetitions of stress on the micro-structure of various metals in the form of crystalline aggregates, the main purpose of the investigation being a study of the causes of fracture under repeated stresses of relatively low magnitude. One important conclusion derived from the experiments was that the action of slipping was not, as had been previously stated, a weakening process in itself. Up to a point the effect of slip was actually to increase the resistance of the metal to further slip. Eventually, however, this strengthening action was exhausted, and failure commenced by the formation of a crack. It was suggested that failure occurred when the amount of strain-hardening by slip exceeded a certain limiting amount. No definite evidence could be obtained on this point, but it was considered that further information might be obtained if attention was directed to a material more simple in structure than a crystalline aggregate. In particular, it was desired to eliminate the effects of the crystal boundaries, whose nature is at present unknown. This could be accomplished if specimens cut entirely from one crystal were employed. Further, it should be possible to verify the assumption, commonly made, that slip bands represent the traces of actual “slip planes” on the surface of the specimen, and to relate these with the atomic structure of the material. Through the kindness of Prof. Carpenter and Miss Elam a number of large single crystals of aluminium were prepared and presented and have been used throughout this work. At that time the necessary experimental facilities for X-ray work were not available to the authors at the National Physical Laboratory. Prof. Carpenter offered to arrange for the X-ray analyses to be undertaken by his assistant, Miss C. F. Elam, at the Royal School of Mines. This offer was gratefully accepted and the authors are greatly indebted to Miss Elam for carrying out this section of the work.

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