K-alpha fluorescence for characterizing Au M-band emission

Conference · Tue Mar 01 04:00:00 EST 1988

OSTI ID:6838262

Phillion, D

The reason for using a fluorescer to measure the energy in a spectral band rather than simply measuring the spectrum directly is that the fluorescer integrates not only over the x-ray energy, but also over angle. It is this average that one is interested in, one measurement takes the place of many. Greater accuracy is also expected. However, the number of fluorescent photons per steradian is usually drastically less than the number of exciting x-ray photons per steradian. This is because of several factors: first, for the low-Z fluorescers we used, the fluorescence efficiency was small. Second, the fluorescer subtended only a small solid angle as seem from the source. This was necessary to allow access to the irradiating beams and lines-of-sight for the diagnostics. Last, beryllium filter reduced the x-ray flux upon the fluorescer and re-absorption of the fluorescence reduced the efficiency still further. The net result was that, in terms of photons/sr, the fluorescence signal was only 0.05% as intense as the total terms Au M-band flux above the fluorescer K-edge. The spectrograph looking at the fluorescence did not look directly at the laser-irradiated spot and did not see the coronal plasma until it had moved out many hundreds of microns. Even so, many gold lines were strongly visible. 6 figs., 2 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6838262
• Report Number(s): UCRL-98417; CONF-880364-; ON: DE88015455
• Country of Publication: United States
• Language: English

Related Subjects

640302 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102* -- Fusion Energy-- Plasma Research-- Diagnostics
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
CHEMICAL ANALYSIS
DISTRIBUTION
EFFICIENCY
ELEMENTS
GOLD
LASER-PRODUCED PLASMA
METALS
NONDESTRUCTIVE ANALYSIS
PLASMA
PLASMA DIAGNOSTICS
SPECTRA
TRANSITION ELEMENTS
X-RAY EMISSION ANALYSIS
X-RAY FLUORESCENCE ANALYSIS
X-RAY SPECTRA