The Quantitative Estimation of the Activity of Beta Particle Emitters (open access)

The Quantitative Estimation of the Activity of Beta Particle Emitters

From abstract: "In estimating the activities of β-emitting materials used in the Biology Section, most measurements were made with Geiger-Mueller counters, although Lauritsen electroscopes were used in early work. All samples were mounted on flat porcelain capsules."
Date: October 3, 1946
Creator: Zinn, Walter H. (Walter Henry), 1906-2000; Broido, Abraham; Nordeen, Clifford & Himmelstein, Sheldon H.
System: The UNT Digital Library
Metabolism and Distribution of Inhaled Plutonium in Rats (open access)

Metabolism and Distribution of Inhaled Plutonium in Rats

From abstract: "Several different techniques were used to introduce tracer quantities of plutonium into the lungs of rats. When aerosols were produced by atomizing aqueous solutions of the nitrates it was found that approximately 20 per cent of the dose was absorbed and deposited in the skelton [sic] with tetra-, hexa-, and trivalent plutonium. Thus with these compounds, the lungs represent a more dangerous portal of entry than either oral (0.05 per cent) or intramuscular (13 per cent) administration. Tetravalent Pu was eliminated most slowly from the lung, the average half-time during the first month being 15 days. But when citrate was added to complex the Pu, over 70 per cent was eliminated within 1 day. This was accompanied by a deposition of over 30 per cent in the skelton [sic] and over 20 per cent in the liver. Presumably citrate breaks up the insoluble colloid in which Pu exists in the lungs. Complexing with cupferron which, unlike citrate, produces a "fat soluble" compound, greatly diminished the extent of absorption from the lungs. Plutonium oxide smokes which were produced at high temperatures were eliminated more slowly from the lungs (average half time of 30 days during the first month) and …
Date: October 29, 1946
Creator: Abrams, Richard; Siebert, H. C.; Potts, A. M.; Forker, L. L.; Greenberg, D.; Postel, A. et al.
System: The UNT Digital Library
The X-Ray Spectra of the Last-Row Elements (open access)

The X-Ray Spectra of the Last-Row Elements

Abstract: X-ray energy level diagrams as given in the literature are tabulated for radium, thorium and uranium. A level scheme for protoactinium is derived from the published data. After a brief review of the use of X-ray data in studying outer electronic structure, it is pointed out that differences in the X-ray spectra should exist depending on whether the outer electrons are in f or d orbitals. The observed separation of the OI and OII levels in thorium and uranium indicated that the f levels lie lower than the d. This hypothesis also provides a reasonable explanation for the observed differences between the MIV and MV absorption edges and MIV and MV levels calculated from the emission spectra and the LIII edge.
Date: October 22, 1946
Creator: Russell, H., Jr.
System: The UNT Digital Library
Radiocarbon from Pile Graphite; Chemical Methods for its Concentration (open access)

Radiocarbon from Pile Graphite; Chemical Methods for its Concentration

Abstract. Samples of pile graphite, irradiated in a test-hole at Hanford for 15 months, have been assayed for radioactive C14, yielding 0.38 ± 0.04 microcuries per gram. At this level of activity, the pile graphite contains very valuable amounts of C14. The relation between the above assay and the probable average assay of pile graphite is discussed, and it is concluded that the latter is almost certainly above 0.3 uc/ gram. Controlled oxidation of this graphite, either with oxygen at ~ 750°C, or with chromic acid "cleaning solution" at room temperature, yields early fractions which are highly enriched in C14. Concentrations of 5-fold with oxygen, and 50-fold with CRO{sub3}, have been observed. The relation between the observed enrichment and the Wigner effect is discussed, and a mechanism accounting for the observations put forward. According to this, about 25% of the stable carbon atoms in the lattice have been displaced by Wigner effect, a large fraction of which have healed the migrating to crystal edges. All the C14 atoms have been displaced, and the same fraction of these migrate to the edges. The enrichment then results from surface oxidation, in the oxygen case. Predictions are made on the basis of this …
Date: October 10, 1946
Creator: Arnold, James R. & Libby, Willard F.
System: The UNT Digital Library