Delivering high-purity vacuum ultraviolet photons at the Brazilian toroidal grating monochromator (TGM) beamline

2007 ◽  
Vol 156-158 ◽  
pp. 168-171 ◽  
Author(s):  
R.L. Cavasso Filho ◽  
A.F. Lago ◽  
M.G.P. Homem ◽  
S. Pilling ◽  
A. Naves de Brito
2007 ◽  
Vol 78 (11) ◽  
pp. 115104 ◽  
Author(s):  
R. L. Cavasso Filho ◽  
M. G. P. Homen ◽  
P. T. Fonseca ◽  
A. Naves de Brito

1988 ◽  
Vol 129 ◽  
Author(s):  
K. L. Tokuda ◽  
B. Pihlstrom ◽  
D. W. Kisker ◽  
M. Lamont Schnoes ◽  
G. J. Collins

ABSTRACTThe growth of high quality ZnSe by organometallic vapor phase epitaxy (OMVPE) has generally been hindered because of parasitic source pre-reactions or relatively high source decomposition temperatures. In this work, we have used vacuum ultraviolet photons generated by a disk-plasma lamp to assist the ZnSe growth process using diethylselenium and diethylzinc as source materials. This approach has resulted in satisfactory growth rates and high material quality at temperatures as low as 250°C, without the limitations of prereaction typically observed when H2Se is used for the selenium source material. In addition, the alkyl selenium compound offers advantages due to reduced toxicity compared to H2Se. This new, low-growth-temperature process thus offers the possibility of improved stoichiometry and impurity incorporation control as well as a reduced thermal effect on the underlying substrate during growth. At the same time, the advantages of excellent morphology and uniformity typically exhibited by the alkylbased growth processes are retained.


1969 ◽  
Vol 24 (6) ◽  
pp. 722-728 ◽  
Author(s):  
K. U. Berger

Inactivation cross sections of infectious ΦΧ-174-DNA in the extreme vacuum-ultraviolet were determined by irradiation of thin layers with monochromatic light down to 584 Å by means of a powerful grating-monochromator, the elements of which are described. Comparison of inactivation and light-induced electron emission shows that light of quantum energies below 7 eV inactivates by excitation only, whereas above 10.2 eV ionization is the predominant inactivation mechanism. Because of the satisfactory agreement of the curves for inactivation and electron emission, it is conducted that the remarkable increase of the inactivation cross section in the region of the short wavelength vacuum-uv is due to increasing ionization probability.


1997 ◽  
Vol 70 (13) ◽  
pp. 1700-1702 ◽  
Author(s):  
R. Singh ◽  
K. C. Cherukuri ◽  
L. Vedula ◽  
A. Rohatgi ◽  
S. Narayanan

2015 ◽  
Vol 22 (2) ◽  
pp. 328-335 ◽  
Author(s):  
Chaofan Xue ◽  
Yanqing Wu ◽  
Ying Zou ◽  
Lian Xue ◽  
Yong Wang ◽  
...  

A new monochromator called an extra-focus constant-included-angle varied-line-spacing (VLS) cylindrical-grating monochromator (extra-focus CIA-VCGM) is described. This monochromator is based on the Hettrick–Underwood scheme where the plane VLS grating is replaced by a cylindrical one in order to zero the defocus at three reference photon energies in the vacuum-ultraviolet range. It has a simple mechanical structure and a fixed focus spot with high performance over a wide energy range. Furthermore, its mechanical compatibility with a standard VLS plane-grating monochromator allows convenient extension into the soft-X-ray range.


2015 ◽  
Vol 22 (6) ◽  
pp. 1353-1358 ◽  
Author(s):  
Chaofan Xue ◽  
Yanqing Wu ◽  
Ying Zou ◽  
Lian Xue ◽  
Zhi Guo ◽  
...  

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.


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