The role of shock acceleration on synchrotron radiation following SL‐9 impact

1995 ◽  
Vol 22 (13) ◽  
pp. 1809-1812 ◽  
Author(s):  
Stephen H. Brecht ◽  
Mark E. Pesses ◽  
Imke de Pater ◽  
N. T. Gladd ◽  
John G. Lyon
Keyword(s):  
Synchrotron Radiation ◽  
Shock Acceleration

Conserving the Coherence and Uniformity of Third-Generation Synchrotron Radiation Beams: the Case of ID19, a `Long' Beamline at the ESRF

1998 ◽  
Vol 5 (5) ◽  
pp. 1243-1249 ◽  
Author(s):  
José I. Espeso ◽  
Peter Cloetens ◽  
José Baruchel ◽  
Jürgen Härtwig ◽  
Trevor Mairs ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Phase Contrast ◽  
Angular Size ◽  
Third Generation ◽  
Optical Elements ◽  
X Ray ◽  
Front End ◽  
Ray Path ◽  
Radiation Beams

The lateral coherence length is of the order of 100 µm at the `long' (145 m) ID19 beamline of the ESRF, which is mainly devoted to imaging. Most of the optical elements located along the X-ray path can thus act as `phase objects', and lead to spurious contrast and/or to coherence degradation, which shows up as an enhanced effective angular size of the source. Both the spurious contrast and the coherence degradation are detrimental for the images (diffraction topographs, tomographs, phase-contrast images) produced at this beamline. The problems identified and the way they were solved during the commissioning of ID19 are reported. More particularly, the role of the protection foils located in the front end, the beryllium windows, the filters and the monochromator defects (scratches, dust, small vibrations) is discussed.

The g factor of an electron in hydrogenlike carbon and the precision determination of the electron mass

2019 ◽  
Vol 34 (28) ◽  
pp. 1941001
Author(s):  
Jonathan Sapirstein
Keyword(s):  
Synchrotron Radiation ◽  
Green Function ◽  
Green Functions ◽  
Electron Mass ◽  
Precision Determination ◽  
High Precision Determination ◽  
Bound Electron ◽  
Modern Form

The role of the bound electron Green function in the recent high precision determination of the electron mass is discussed. Emphasis is placed on the connection to Schwinger’s use of such Green functions in his early work establishing the modern form of QED, his calculation of leading binding corrections, and his work on synchrotron radiation.

Gamma-Ray Solar Flares and In Situ Particle Acceleration

2017 ◽  
Vol 13 (S335) ◽  
pp. 43-48 ◽  
Author(s):  
Alexei Struminsky
Keyword(s):  
Gamma Ray ◽  
Solar Energetic Particle ◽  
High Energy ◽  
Shock Acceleration ◽  
Relative Role ◽  
Energy Gamma ◽  
Mass Ejection ◽  
Flare Site

AbstractAt present two concurrent paradigms of solar energetic particle (SEP) origin exist: acceleration directly in the flare site or by the shock wave of coronal mass ejection (CME). Active discussions on a relative role of flares and coronal mass ejections for SEP acceleration and propagation are continuous until now. In my opinion only future observations of solar high energy γ–emission with better spectral, spatial and temporal resolution may clarify this issue. In my report I discuss possible signatures of the flare and shock acceleration processes. What is a picture provided by the current instruments? What can we expect to observe with a perfect instrument in high energy gamma rays in one or another case on a time scale of impulsive and long decay flare phases?

scholarly journals Dynamics of Single­ and Multi-photon Ionisation Processes in Molecules

1986 ◽  
Vol 39 (5) ◽  
pp. 761 ◽  
Author(s):  
V McKoy ◽  
SN Dixit ◽  
RL Dubs ◽  
DL Lynch
Keyword(s):  
Synchrotron Radiation ◽  
Cross Sections ◽  
Single Photon ◽  
Realistic Model ◽  
Dye Lasers ◽  
Linear Molecules ◽  
Dynamical Information

Single-photon ionisation and resonant multiphoton ionisation studies, which can now be carried out using synchrotron radiation and pulsed dye lasers respectively, are providing important dynamical information on molecular photoionisation. In this paper we discuss some results of our recent studies of several, single- and multi-photon ionisation processes in molecules. The results will be taken from our studies of (i) single-photon ionisation of linear molecules with emphasis on the role of shape and autoionising resonances on these cross� sections, (ii) photoionisation from oriented NiCO as a simple but realistic model of photoemission in adsorbate-substrate systems, and (iii) resonant multiphoton ionisation of H2.

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