ELECTRON SPECTRA IN THE DECAY OF THALLIUM-204

1967 ◽  
Vol 45 (8) ◽  
pp. 2621-2637 ◽  
Author(s):  
J. J. H. Park ◽  
P. Christmas
Keyword(s):  
High Resolution ◽  
Shape Factor ◽  
Fluorescence Yield ◽  
Auger Line ◽  
Beta Spectrum ◽  
Point Energy ◽  
Broad Agreement ◽  
Electron Spectra ◽  
Double Focusing ◽  
Instrumental Distortion

The continuous beta spectrum and the K Auger-line spectrum in the decay of 204Tl were investigated using a high-resolution, iron-free, [Formula: see text] double-focusing spectrometer. Instrumental distortion of the beta spectrum was shown to be very small and a linear Fermi–Kurie plot was obtained using the generalized unique first forbidden shape factor bq2 + λ2p2, with b = 1.161 ± 0.005. The end-point energy was determined to be (763.24 ± 0.31) keV. Measured values for the energies and relative intensities of the K Auger lines were in broad agreement both with theory and with previous experimental work. The K fluorescence yield was estimated to be 0.97 ± 0.017.

THE DECAY OF Pm149

1960 ◽  
Vol 38 (12) ◽  
pp. 1577-1585 ◽  
Author(s):  
Agda Artna ◽  
Margaret E. Law
Keyword(s):  
High Resolution ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Conversion Coefficient ◽  
Beta Spectrum ◽  
Multichannel Analyzer ◽  
Coincidence Spectrometer ◽  
Beta Spectrometer ◽  
Beta Group

The 52.8-hour activity of Pm149 has been investigated using a high resolution beta spectrometer, a lens type coincidence spectrometer, and a scintillation spectrometer in conjunction with a multichannel analyzer. The beta spectrum was found to consist of two groups with maximum energies of 1.072 ± 0.002 Mev and 0.786 ± 0.004 Mev, and intensities of 97.1 ± 0.4% and 2.9 ± 0.4% respectively. A gamma ray of energy 285.7 ± 0.3 kev was found to be in coincidence with the 0.786-Mev beta group. No other gamma rays with intensities greater than 0.1% were found. The K conversion coefficient for the 286-kev transition was measured to be 0.075 ± 0.008. This together with the values of 6.5 ± 0.7 and 4 ± 1 obtained for the K/L and L/M conversion ratios respectively indicate that this transition is M1 in character with less than 10% E2 admixture.

High resolution L2,3M2,3M2,3Auger electron spectra of argon

1973 ◽  
Vol 6 (6) ◽  
pp. L156-L158 ◽  
Author(s):  
T Kondow ◽  
T Kawai ◽  
K Kunimori ◽  
T Onishi ◽  
K Tamaru
Keyword(s):  
High Resolution ◽  
Electron Spectra

High resolution beam gas Auger electron spectra for oxygen ions excited by collisions with He, Ne, and Ar

1975 ◽  
Vol 53 (3) ◽  
pp. 254-256 ◽  
Author(s):  
B.M. Johnson ◽  
D. Schneider ◽  
K.S. Roberts ◽  
J.E. Bolger ◽  
C.F. Moore
Keyword(s):  
High Resolution ◽  
Auger Electron ◽  
Oxygen Ions ◽  
Electron Spectra ◽  
Auger Electron Spectra

High Resolution Auger Imaging Combined with Focused Ion Beam for the Investigation of Metal/GaAs Contacts in High Power Transistors

1998 ◽  
Vol 514 ◽  
Author(s):  
Patrick Etienne ◽  
Jean-Pierre Landesman ◽  
Frederic Wyczisk ◽  
Simone Cassette ◽  
Sylvain Delage
Keyword(s):  
High Resolution ◽  
High Power ◽  
Auger Electron ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Concentration Profiles ◽  
Atomic Concentration ◽  
Power Transistors ◽  
Electron Spectra ◽  
Auger Electron Spectra

ABSTRACTInspecting and understanding the thermal stability of metal contacts in the context of reliability testing on high power transistors (especially in the GaAs technology) often necessitates to view atomic concentration profiles at deep interfaces. One common method for this purpose is the combined Auger spectroscopy/ion etching technique, where the region to be investigated is etched sequentially (with a “low” etch rate, typically in the Å/second regime) and Auger electron spectra (AES) are recorded at each step of the etching process. The 3 major resolution drawbacks of this approach are first that it is time-consuming, second that the spatial resolution is limited (atomic profiles on contact regions with lateral dimensions smaller that I R~m are difficult to obtain) and third that the interface of interest is “smoothed” during the etch process. The third point yields atomic concentration profiles with an apparent inter-mixing, which sometimes hinders observation of the details of interest for the interface under investigation.We have used a different approach for this aspect of metal contact testing, in which the interface to be studied is first “revealed” by focused ion beam (FIB) micro-sectioning. After this preparation step, chemical images of the interface are directly obtained by high resolution Auger electron spectra mapping. The different operating conditions for the FIB process (orientation of the cross-section with respect to the transistor surface, preliminary procedures to eliminate residual roughness as well as surface contamination) have been optimized in order to produce Auger spectra free of any artifact. The approach is demonstrated on Au/GeNiAu ohmics contacts to the emitter electrode of GaAs-based hererostructure bipolar transistor, designed for high power amplification in the microwave regime. Ultimate spatial resolution of 20 to 30 nm on the Ayuger chemical images is demonstrated on an Auger microscope equipped with a Schottky field emitting tip.

Anomalous L-Subshell Internal Conversion of Some Hindered El Transitions in 171Tm, 175Lu and 177Hf

1973 ◽  
Vol 28 (12) ◽  
pp. 1959-1964 ◽  
Author(s):  
M. S. El-Nesr ◽  
E. Bashandy
Keyword(s):  
High Resolution ◽  
Experimental Evidence ◽  
Electric Dipole ◽  
Conversion Electron ◽  
Internal Conversion ◽  
Conversion Process ◽  
Dynamic Effects ◽  
Internal Conversion Electron ◽  
Theoretical Predictions ◽  
Double Focusing

The L-subshell internal conversion electron ratios of some hindered electric dipole transitions in the odd-mass nuclei 171Tm, 175Lu and 177 Hf have been measured by means of a high resolution ironfree double focusing beta-ray spectrometer. Large anomalies have been observed in the conversion process. The anomalies are interpreted as an experimental evidence for the presence of dynamic effects. The internal conversion penetration parameters have been determined. The results obtained are discussed in terms of theoretical predictions.

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