BEAT STRUCTURE IN THE DOUBLY EXCITED RYDBERG STATES CONVERGING TO THE N = 2 THRESHOLD OF HELIUM

2002 ◽  
Vol 09 (01) ◽  
pp. 165-168 ◽  
Author(s):  
R. FOLLATH ◽  
G. Reichardt ◽  
O. SCHWARZKOPF ◽  
W. GUDAT
Keyword(s):  
High Performance ◽  
Rydberg States ◽  
Principal Series ◽  
Resolving Power ◽  
Electron Interaction ◽  
Coupling Scheme ◽  
High Excitation ◽  
Doubly Excited ◽  
Grating Monochromator ◽  
Very High

The N = 2 double excitation series of helium was examined with the high performance U125 plane grating monochromator at BESSY II set to a resolving power of 90 000. A hitherto unresolved beat structure in the principal series was observed at very high excitation levels. The beat can be explained by the mixing of two series converging to different ionization thresholds and having an energy spacing corresponding to the energy split between the 2p1/2 and the 2p3/2 level of singly ionized helium. This indicates that the electron interaction at high excitation levels must be described within the JK coupling scheme.

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.

A unique high-performance wide-range (10–1500 eV) spherical grating monochromator beamline

1998 ◽  
Vol 5 (3) ◽  
pp. 723-725 ◽  
Author(s):  
P.-C. Tseng ◽  
C.-C. Chen ◽  
T.-E. Dann ◽  
S.-C. Chung ◽  
C. T. Chen ◽  
...  
Keyword(s):  
High Performance ◽  
Low Energy ◽  
Resolving Power ◽  
Photon Flux ◽  
Wide Spectral Range ◽  
Experimental Station ◽  
Wide Range ◽  
Grating Monochromator ◽  
Overall Performance ◽  
Under Construction

A wide-spectral-range high-performance 6 m-spherical grating monochromator (6 m-SGM) beamline has been designed and is under construction at SRRC. Two different entrance slits, instead of additional mirrors, are used to optimize the overall performance. Six gratings are used to cover photon energies from 10 to 1500 eV. Movable entrance slits and bendable vertical focusing mirrors are used to enhance further the beamline performance. A bendable horizontal focusing mirror is used to improve the resolution and to focus the photon beam at the experimental station immediately after the exit slit. Several end-stations can be installed at the same time to utilize the beam time fully. The expected energy-resolving power, with both slit openings set at 10 µm, is up to 15 000 and 40 000 for the high- and low-energy branches, respectively. A photon flux of 1 × 1011 photons s−1 can be obtained with an energy-resolving power of 20 000.

KEMPER C688

Alloy Digest ◽  
2017 ◽  
Vol 66 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
High Performance ◽  
High Conductivity ◽  
Bend Strength ◽  
Very High

Abstract Alloy C688 is a high-performance copper alloy with very high conductivity. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming and joining. Filing Code: Cu-867. Producer or source: Gebr. Kemper GmbH + Company KG Metallwerke.

KEMPER KHP7025

Alloy Digest ◽  
2017 ◽  
Vol 66 (10) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
High Performance ◽  
High Conductivity ◽  
Bend Strength ◽  
Very High

Abstract Alloy KHP 7025 (UNS C70250) is a high-performance copper alloy with very high conductivity. Uses include connector springs, tabs, contact springs, switches, relays, and leadframes. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: Cu-865. Producer or source: Gebr. Kemper GmbH + Company KG Metallwerke.

Use of activated carbon to remove undesirable residual amylase from refinery streams

2017 ◽  
pp. 96-103 ◽  
Author(s):  
Gillian Eggleston ◽  
Isabel Lima ◽  
Emmanuel Sarir ◽  
Jack Thompson ◽  
John Zatlokovicz ◽  
...  
Keyword(s):  
Activated Carbon ◽  
High Temperature ◽  
High Performance ◽  
Activated Carbons ◽  
Amylase Activity ◽  
Sugar Industry ◽  
End User ◽  
Customer Complaints ◽  
Carry Over ◽  
Very High

In recent years, there has been increased world-wide concern over residual (carry-over) activity of mostly high temperature (HT) and very high temperature (VHT) stable amylases in white, refined sugars from refineries to various food and end-user industries. HT and VHT stable amylases were developed for much larger markets than the sugar industry with harsher processing conditions. There is an urgent need in the sugar industry to be able to remove or inactivate residual, active amylases either in factory or refinery streams or both. A survey of refineries that used amylase and had activated carbon systems for decolorizing, revealed they did not have any customer complaints for residual amylase. The use of high performance activated carbons to remove residual amylase activity was investigated using a Phadebas® method created for the sugar industry to measure residual amylase in syrups. Ability to remove residual amylase protein was dependent on the surface area of the powdered activated carbons as well as mixing (retention) time. The activated carbon also had the additional benefit of removing color and insoluble starch.

scholarly journals Hyperfine structure in the arc spectrum of cæsium and nuclear rotation

1928 ◽  
Vol 121 (787) ◽  
pp. 432-447 ◽  
Keyword(s):  
Hyperfine Structure ◽  
Nuclear Spin ◽  
High Frequency ◽  
Principal Series ◽  
Very High Frequency ◽  
Nuclear Rotation ◽  
Higher Temperature ◽  
The Difference ◽  
Mechanical Moment ◽  
Very High

The arc spectrum of cæsium was investigated with the object of finding whether any of its lines possessed hyperfine structure, resulting from a nuclear magnetic moment, due to a quantised nuclear spin. The lines belonging to the principal series should, owing to the greater degree of penetration of the electron in the (1 s or 6 1 ) orbit, and the correspondingly greater interaction, show the greatest effect. The lines of the principal series are very easily broadened if the vapour pressure of the metal becomes high, so that great care had to be used in obtaining the spectrum of cæsium at a sufficiently low temperature. The most satisfactory method of excitation was found to be the application by means of external electrodes of a very high frequency alternating current to a tube filled with helium at about 2 mm. pressure containing a small quantity of cæsium. The tube required slight heating to bring out the cæsium lines; without this the helium spectrum was very much stronger than the metallic spectrum. At a very low vapour pressures of cæsium the discharge was blue in colour. Under these conditions the lines of the principal series showed no broadening greater than that due to thermal agitation, but at a slightly higher temperature the colour of the discharge became purple and the lines broadened. The lines belonging to the principal series were found to be very close doublets with very nearly constant frequencies differences. A theory is worked out which explains the origin of these doublets, assuming a nuclear spin of one half quantum; by correlating the difference in the separation of the hyperfine structure doublets in the 1 s — m 2 p 3/2 lines and the 1 s — m 2 p 1/2 lines, it is shown that a ratio of the magnetic to the mechanical moment of the nucleus about twice as great as the corresponding ratio for the electron would account for the observed frequency differences. The spectral notation used throughout is that of Hund. The results are compared with those found for the hyperfine structure of some of the bismuth lines by Back and Goudsmid, and are found to be in satisfactory agreement. A selection principle is found which applies both to the bismuth and the cæsium spectrum.

Frost Durability of Very High Performance Cement-Based Materials

1999 ◽  
Vol 11 (2) ◽  
pp. 167-170 ◽  
Author(s):  
Luigi Biolzi ◽  
Gian Luca Guerrini ◽  
Gianpaolo Rosati
Keyword(s):  
High Performance ◽  
Cement Based Materials ◽  
Frost Durability ◽  
Very High

Vibration-rotation bands and rotational constants of dideuteroacetylene

1955 ◽  
Vol 232 (1190) ◽  
pp. 291-309 ◽  
Keyword(s):  
Resolving Power ◽  
Vibrational States ◽  
Absorption Bands ◽  
Rotational Constants ◽  
Vibrational Assignments ◽  
Vibrational Anharmonicity ◽  
A Value ◽  
Vibrational Levels ◽  
Vibration Rotation ◽  
Very High

Nine vibrational absorption bands of dideutero-acetylene have been examined with very high resolving power. The rotational constants have been determined for the vibrational levels concerned, and the coefficients α i have been determined with more convincing accuracy than previously. In some of the bands the Q branches have been resolved, so that the l -doubling coefficients q i could be derived, and details could be established about the doublet components in some II levels. The results emphasize the need of high resolution if the vibrational assignments are to be unambiguous, and if reliable values of the rotational constants are to be derived. A value of B e has been obtained, and the vibrational anharmonicity coefficients have been considered briefly. Estimates of the centrifugal stretching constants D i in different vibrational states have been made, and one anomalous case has been found.

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