OPTICAL METHODS OF ISOTOPE RATIO DETERMINATION

Technical Report · Fri Oct 31 04:00:00 EST 1958

OSTI ID:4326832

Brody, J K; Tomkins, F S

In the methods developed for H/sup 1/, H/sup 2/, H/sup 3/ and He/sup 3/, He/s up 4/, electrodeless discharge tubes were used and the lines resolved with a grating spectraograph. Initially, intensity measurements were made photographically but later improved with direct photoelectric scannning of the spectrum. The Li/sup 6/, Li/sup 7/ isotope shift in the lambda 6707 A line was resolved in the fourth order of a large concave terferometer. In order to reduce the Doppler broadening of the lines of liquid air cooled hollow cathode tube was developed. The U/sup 235/, U/sup 238/ isotope pair for thee lambda 4244.37 A line was resolved directly by the grating. Both the water cooled hollow cathode tube and the high voltage condensed AC spark were used to excite the sample. With the former source, the accuracy of the isotope ratios compared well with the mass spectrometric resalt. With the spark source, the determinations were made considerably more rapidly but with some sacrifice in accuracy. For small isotope shifts of the order of 0.01 A, a scanning Fabry-Perot interferometer was developed in which the optical path between the plates was varied by changing the pressure. The fringe intensity was measured by a photomulitiplier tube, and a typical recorder trace of Pb/sup 204/, Pb/sup 206/, Pb/sup 208/ and components of Pb/sup 207/ for lambda 4058 is shown. Known mixtures of separated isotopes as well as comparisons with mass spectrometric values for normal lead were used to test the method. Normal mercury was assigned isotopically using the line lambda 4047 for the odd, 199/201 ratio and the 2536 line in the tenth order for the even isotope ratios. The results compared favorably with mass spectrametric value for normal mercury. (auth)

• Research Organization: Argonne National Lab., Lemont, Ill.
• NSA Number: NSA-12-014901
• OSTI ID: 4326832
• Report Number(s): A/CONF.15/P/945
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AIR
CATHODES
COOLING
DEUTERIUM
ELECTRIC DISCHARGES
EXCITATION
HELIUM 3
HELIUM 4
HYDROGEN
LEAD 204
LEAD 206
LEAD 207
LEAD 208
LIQUEFYING
LIQUIDS
LITHIUM 6
LITHIUM 7
MASS SPECTROMETERS
MEASURED VALUES
MERCURY 199
MERCURY 201
PHOTOELECTRIC EFFECT
PHOTOMULTIPLIERS
PHYSICS
PRESSURE
SPECTRA
SPECTROMETERS
TRITIUM
TUBES
URANIUM 235
URANIUM 238