Extreme ultraviolet radiation

D. Attwood, Soft X-rays and Extreme Ultraviolet Radiation (Cambridge University Press, Cambridge, 1999)... 

Ionization chambers and Geiger counters can be used for detecting extreme ultraviolet radiation. Knowledge of the ionization efficiency of the gas makes it possible to use them for measurement of absolute energy. Ultraviolet radiation also can be detected with a thermocouple, thermopile, or bolometer. 

Attwood, D.T. Soft X-Rays and Extreme Ultraviolet Radiation Principles and Applications, Cambridge University Press, New York, NY. 1999. 

The measurement of extreme ultraviolet radiation (EUV) emitted from magnetically confined fusion plasmas deals principally with the study of line emissions from highly ionized inpurities in the hot plasma ( 1 ). The 500-1600 A spectral range includes the major An = 0 transitions of common intrinsic low-Z impurities such as carbon and oxygen, while the 100-500 A range contains the principal lines from highly ionized metals such as Fe, Ti, and Ni. In a hot plasma with central electron... 

The largest variability in solar output is generally observed at the shortest wavelengths. Extreme ultraviolet radiation varies by a factor of two or more over an 11-year solar cycle, and produces nitric oxide in the thermosphere. As already mentioned, NO can be transported to the mesosphere and, to some extent, in winter even to the upper stratosphere where it can perturb upper stratospheric ozone. This is an indirect mechanism linking solar activity at short wavelengths (which do not penetrate below the lower thermosphere) to chemistry at lower altitudes. 

The F-region begins above 130 km and is sometimes subdivided into two layers, Fi and F2. It is primarily produced by ionization of atomic oxygen and molecular nitrogen by extreme ultraviolet radiation (9-91 nm). The atomic oxygen ion, 0+, dominates. The electron density attains its maximum value of about 106cm-3 in this layer. The F-region plays an important role in the transmission of certain radio waves, which... 

Anxolabeheie-Mallart E, Glaser T, Frank P, Aliverti A, Zanetti G, Hedman B, Hodgson , Solomon El (2001) Sulfur -edge X-ray absorption spectroscopy of 2Fe-2S Fenedoxin Covalency of the oxidized and reduced 2 Fe forms and comparison to model complexes. J Am Chem Soc 123 5444-5452 Apen E, Hitchcock AP, Gland JL (1993) Experimental studies of the core excitation of imidazole, 4,5-dicyanoimidazole, and s-triazine J Phys Chem 97 6859-6866 Attwood DT (2000) Soft X-rays and Extreme Ultraviolet Radiation Principles and Applications. Cambridge, New York... 

G. Z. Zhang, D. W. Tokaryk, B. P. Stoicheff, K. Hakuta. Nonlinear generation of extreme-ultraviolet radiation in atomic hydrogen using electromagnetically induced transparency. Physical Revew A 1997 Dec 2 56(1) 813-819. 

Measurements of ozone (O3) concentrations in the atmosphere are of particular importance. Ozone absorbs strongly in the ultraviolet region and it is this absorption which protects us from a dangerously high dose of ultraviolet radiation from the sun. The vitally important ozone layer lies in the stratosphere and is typically about 10 km thick with a maximum concentration about 25 km above the surface of the earth. Extreme depletion of ozone in a localised part of the atmosphere creates what is known as an ozone hole. 

Here, we shown a "conventional" system. It consists of a light source, an etched, transparent circuit diagram and a lens to focus the pattern upon the wafer which has a photoresist layer. Upon exposure, the unexposed part of the photoresist is wzished off. Sometimes, the exposed area is removed, depending upon weather the photoresist is positive or negative. Contrast this simple system with a method under development is the "Extreme Ultraviolet (EUV) system, using radiation from excited Xe gas, i.e.- 157 nm. The EUV system is shown in the following ... 

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