A variable fixed-focus constant optimization method for a variable-included-angle varied-line-spacing plane-grating monochromator

2019 ◽  
Vol 26 (4) ◽  
pp. 1192-1197 ◽  
Author(s):  
Chaofan Xue ◽  
Lian Xue ◽  
Yanqing Wu ◽  
Yong Wang ◽  
Shumin Yang ◽  
...  
Keyword(s):  
Optimization Method ◽  
The Self ◽  
Resolving Power ◽  
Correction Function ◽  
Aberration Correction ◽  
Included Angle ◽  
Variable Line ◽  
Self Focusing ◽  
Line Spacing ◽  
Grating Monochromator

Variable-included-angle varied-line-spacing plane-grating monochromators (VIA-VPGM) have been applied to many beamlines because of the self-focusing and aberration-correction function of the varied-line-spacing grating. Unfortunately, to optimize the variable-line-spacing coefficient of the grating, the fixed-focus constant (C ff) has to be fixed first in the VIA-VPGM. In this way, some of the advantages of these monochromators are lost, such as the flexibility of choosing a different energy-resolving power by varying the C ff. In this work, a variable C ff optimization method is introduced for a VIA-VPGM. By adopting this method, the C ff could be arbitrarily selected in the VIA-VPGM.

Applications of VUV extra-focus mechanism: high-performance dual-mode monochromator from VUV to soft X-ray

2015 ◽  
Vol 22 (6) ◽  
pp. 1353-1358 ◽  
Author(s):  
Chaofan Xue ◽  
Yanqing Wu ◽  
Ying Zou ◽  
Lian Xue ◽  
Zhi Guo ◽  
...  
Keyword(s):  
High Performance ◽  
Vacuum Ultraviolet ◽  
Normal Incidence ◽  
Resolving Power ◽  
Dual Mode ◽  
Included Angle ◽  
X Ray ◽  
Line Spacing ◽  
Grating Monochromator ◽  
Mode Solution

A new monochromator scheme is presented in which an extra-focus constant-included-angle varied-line-spacing cylindrical-grating monochromator (extra-focus CIA-VCGM) is conveniently combined with a variable-included-angle varied-line-spacing plane-grating monochromator (VIA-VPGM). This dual-mode solution delivers high performance in the energy range from vacuum ultraviolet (VUV) to soft X-ray. The resolving power and the efficiency of this dual-mode grating monochromator are analyzed in detail based on realistic parameters. Comparisons with the commonly used variable-included-angle plane-grating monochromator and normal-incidence monochromator (VIA-PGM/NIM) hybrid monochromator are made.

Variable line spacing plane grating monochromator for first LNLS undulator beamline

2011 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
F. Rodrigues ◽  
R. T. Neuenschwander ◽  
L. F. Ribeiro ◽  
M. Rocha ◽  
T. J. da Silva ◽  
...  
Keyword(s):  
Storage Ring ◽  
Resolving Power ◽  
Variable Line ◽  
Line Spacing ◽  
Grating Monochromator ◽  
Elliptically Polarized ◽  
Design And Construction

In early 2007 an elliptically polarized Apple II undulator was installed on an LNLS storage ring. It will provide photons to the first PGM beamline at LNLS designed to deliver photons ranging from 100 to 1000 eV with a resolving power of over 10 000. The beamline is about to start the commissioning process and this paper describes mainly the monochromator design and construction.

Commissioning of a Soft X-ray Beamline PF-BL-16A with a Variable-Included-Angle Varied-Line-Spacing Grating Monochromator

2010 ◽  
Author(s):  
Kenta Amemiya ◽  
Akio Toyoshima ◽  
Takashi Kikuchi ◽  
Takashi Kosuge ◽  
Kazuyuki Nigorikawa ◽  
...  
Keyword(s):  
Included Angle ◽  
X Ray ◽  
Line Spacing ◽  
Grating Monochromator

Commissioning and performance of the variable line spacing plane grating monochromator beamline at the Canadian Light Source

2007 ◽  
Vol 78 (8) ◽  
pp. 083109 ◽  
Author(s):  
Y. F. Hu ◽  
L. Zuin ◽  
G. Wright ◽  
R. Igarashi ◽  
M. McKibben ◽  
...  
Keyword(s):  
Light Source ◽  
Variable Line ◽  
Line Spacing ◽  
Grating Monochromator ◽  
And Performance

Combined influence of axial electron temperature and exponential plasma density ramp on the self-focusing of a chirped laser in plasma

2020 ◽  
Vol 75 (7) ◽  
pp. 671-675
Author(s):  
Niti Kant ◽  
Vishal Thakur
Keyword(s):  
Electron Temperature ◽  
Pulse Laser ◽  
Plasma Density ◽  
Beam Width ◽  
Spot Size ◽  
Higher Order ◽  
The Self ◽  
Chirped Pulse ◽  
Self Focusing ◽  
Paraxial Ray

AbstractAn analysis of the self-focusing of highly intense chirped pulse laser under exponential plasma density ramp with higher order value of axial electron temperature has been done. Beam width parameter is derived by using paraxial ray approximation and then solved numerically. It is seen that self-focusing of chirped pulse laser is intensely affected by the higher order values of axial electron temperature. Further, influence of exponential plasma density ramp is studied and it is concluded that self-focusing of laser enhances and occurs earlier. On the other hand defocusing of beam reduces to the great extent. It is noticed that the laser spot size reduces significantly under joint influence of the density ramp and the axial electron temperature. Present analysis may be useful for the analysis of quantum dots, the laser induced fusion and etc.

Relativistic self-focusing of a rippled laser beam in a plasma

1999 ◽  
Vol 62 (4) ◽  
pp. 389-396 ◽  
Author(s):  
M. V. ASTHANA ◽  
A. GIULIETTI ◽  
DINESH VARSHNEY ◽  
M. S. SODHA
Keyword(s):  
Refractive Index ◽  
Laser Beam ◽  
The Self ◽  
Laser Beams ◽  
Radial Dependence ◽  
Main Beam ◽  
Gaussian Laser Beam ◽  
Self Focusing ◽  
Saturation Effects ◽  
Paraxial Ray

This paper presents an analysis of the relativistic self-focusing of a rippled Gaussian laser beam in a plasma. Considering the nonlinearity as arising owing to relativistic variation of mass, and following the WKB and paraxial-ray approximations, the phenomenon of self-focusing of rippled laser beams is studied for arbitrary magnitude of nonlinearity. Pandey et al. [Phys. Fluids82, 1221 (1990)] have shown that a small ripple on the axis of the main beam grows very rapidly with distance of propagation as compared with the self-focusing of the main beam. Based on this analogy, we have analysed relativistic self-focusing of rippled beams in plasmas. The relativistic intensities with saturation effects of nonlinearity allow the nonlinear refractive index in the paraxial regime to have a slower radial dependence, and thus the ripple extracts relatively less energy from its neighbourhood.

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