Deuteron bombardment of the heavy elements.

The results of the bombardment of mercury, lead and thallium by 9 M.e.V. deuterons are reported. The following radioactive isotopes have been detected: 5·5 min., 48 min., 36 hr., 60 day mercury isotopes; 4·4 min., 10·5 hr., 44 hr., and 13 day thallium isotopes; 10·25 min., 2·75 hr., and 54 hr. lead isotopes; 18 hr. and 6·35 day bismuth isotopes. The 10·25 min. lead isotope is positron emitting, an interesting result in an element of high atomic number. Absorption measurement have been made of the radiations emitted by many of these isotopes and assignments have been made in most cases.In conclusion we wish to thank Dr N. Feather for valuable discussions, and also for making for us a Ra E source. We are indebted to Dr Lewis for advice in setting up the thyratron scale of eight counter. This paper would be incomplete without a sincere acknowledgement of our indebtedness to the hard work of past members of this laboratory who have been mainly responsible for setting up the cyclotron.One of us (R. S. K.) is grateful to the Royal Commissioners for the Exhibition of 1851 for the grant of an overseas scholarship which made this work possible.

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Areas for Improvement in XRF Analysis of Low Atomic Number Elements

Advances in X-ray Analysis ◽

10.1154/s0376030800018668 ◽

1992 ◽

Vol 36 ◽

pp. 73-80

Author(s):

Bruno A.R. Vrebos ◽

Gjalt T.J. Kuipéres

Keyword(s):

Lower Limit ◽

Atomic Number ◽

Energy Dispersive Spectrometry ◽

Limit Of Detection ◽

Heavy Elements ◽

Fluorescence Spectrometry ◽

Accurate Analysis ◽

X Ray ◽

Made In

Accurate analysis of the light elements has been, from the early applications of X-ray fluorescence spectrometry a struggle compared to the determination of heavy elements in the same matrices. In contrast, there has been virtually no upper limit to the atomic number of the element that could be determined. The lower limit, however, has been continuously adjusted downward through the years. Clearly, the sensitivity as well as the lower limit of detection for the heavy elements have also been improved, but the effect is Jess striking than the advances made in the region of tight element performance. This paper deals specifically with wavelength dispersive sequential x-ray fluorescence spectrometry, although some of the observations made are equally applicable to energy dispersive spectrometry.

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THE ABSORPTION OF GAMMA-RAYS FROM Co60

Canadian Journal of Research ◽

10.1139/cjr47a-026 ◽

1947 ◽

Vol 25a (6) ◽

pp. 303-314 ◽

Cited By ~ 12

Author(s):

W. V. Mayneord ◽

A. J. Cipriani

Keyword(s):

Absorption Coefficient ◽

Atomic Number ◽

Gamma Rays ◽

Heavy Elements ◽

Photoelectric Absorption ◽

Lead Absorber ◽

Absorption Coefficients ◽

Cobalt Radiation ◽

Good Agreement ◽

Made In

Measurements of the absorption of gamma-rays from Co60 and radium have been made in a number of materials. Variation of absorption coefficient of the gamma-rays from radium with thickness of lead absorber is in agreement with recent experimental determinations. The gamma-rays from Co60 are approximately monochromatic and are therefore suitable for testing theoretical absorption formulae. The absorption coefficient per electron for materials of atomic number equal to or less than that of aluminium was in agreement with the Klein–Nishina formula, assuming the cobalt radiation to consist of two lines at 1.10 and 1.30 Mev. respectively. The photoelectric absorption coefficients per electron for heavy elements are in good agreement with the theory developed by Hulme, McDougall, Buckingham, and Fowler. This coefficient varies approximately as Z3.5.

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Deuteron bombardment of the heavy elements

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100018041 ◽

1941 ◽

Vol 37 (4) ◽

pp. 422-432 ◽

Cited By ~ 12

Author(s):

R. S. Krishnan ◽

E. A. Nahum

Keyword(s):

Excitation Function ◽

Yield Curve ◽

Radioactive Isotopes ◽

Heavy Elements ◽

Energy Yield ◽

Deuteron Bombardment ◽

Γ Rays ◽

Platinum Isotope

Experiments on the bombardment of platinum with 9 M.e.V. deuterons are reported. Radioactive isotopes of platinum of periods 32 min., 18 hr. and 2·8 days, and isotopes of gold of periods 2·6 and 5·6 days are reported. The 2·6 day gold isotope is formed directly by deuteron bombardment as well as by decay of the 32 min. platinum isotope. The absorption of the β-rays in aluminium and of the γ-rays in lead has been measured, and assignments have been made for most of the isotopes reported. Excitation function measurements have been made for the 32 min. and 18 hr. platinum isotopes, and the form of the energy-yield curve is the same for both these elements. The form of the curve seems to favour the Oppenheimer-Phillips process for the formation of these radioelements by the reaction.

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