Alpha-Decay in Isotopes of Atomic Number Less Than 83 (open access)

Alpha-Decay in Isotopes of Atomic Number Less Than 83

Some time ago we started work in an attempt to observe alpha-particle decay in isotopes of atomic number less than 83. In the first experiments, thin targets of gold leaf were bombarded with 190-Mev deuterons in the 184-inch cyclotron. Two alpha-decay periods were observed in these targets; one of 0.7 minutes half-life and another of 4.3 minutes half-life. The alpha-particle energies were 5.7 and 5.2 Mev, respectively. Chemical separations proved that the 4.3-minute period is due to a gold isotope and suggested that the 0.7-minute period is due to a mercury isotope. The mass numbers of these new isotopes have not been determined. However, the results of excitation-functions in the production of the gold isotope by bombarding gold and platinum with protons suggest that its mass number lies in the range 185-188. The work on this isotope indicates that the alpha to electron capture branching ratio is of the order of magnitude of 10{sup -4}, and that positron activity accompanies the 4.3-minute alpha-period.
Date: September 5, 1949
Creator: Thompson, S. G.; Ghiorso, A.; Radmussen, J. O. & Seaborg, G. T.
Object Type: Report
System: The UNT Digital Library
Electronic Structure of the Heaviest Elements (open access)

Electronic Structure of the Heaviest Elements

All of the available evidence leads to the view that the 5f electron shell is being filled in the heaviest elements giving rise to a transition series which begins with actinium in the same sense that the rare earth or 'lanthanide' series begins with lanthanum. Such an 'actinide' series is suggested on the basis of evidence in the following lines: (1) chemical properties, (2) absorption spectra in aqueous solution and crystals, (3) crystallographic structure data, (4) magnetic susceptibility data and (5) spectroscopic data. The salient point is that the characteristic oxidation state (i.e., the oxidation state exhibited by the member containing seven 5f and presumably also by the member containing fourteen 5f electrons, curium and element 103) is the III state, and the group is placed in the periodic table on this basis. The data also make it possible to give a suggested table of electronic configurations of the ground state of the gaseous atom for each of the elements from actinium to curium inclusive.
Date: July 14, 1948
Creator: Seaborg, G. T.
Object Type: Report
System: The UNT Digital Library
Monthly Progress Report No. 58 for February 1948 (open access)

Monthly Progress Report No. 58 for February 1948

This is a monthly progress report on the following programs: (1) 184-inch Cyclotron; (2) 60-inch Cyclotron; (3) Synchrotron; (4) Linear Accelerator; (5) Experimental Physics; (6) Theoretical Physics; (7) Isotope Research; (8) Chemistry; (9) Medical Physics; and (10) Health Physics and Chemistry.
Date: February 1, 1948
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Path of Carbon in Photosynthesis II. Amino Acids (open access)

The Path of Carbon in Photosynthesis II. Amino Acids

The radioactive amino acid's synthesized from C{sup 14}O{sub 2} by green algae both in the light and in the dark after CO{sub 2}-free preillumination have been separated and identified using paper chromatography and radioautography. The radioactive amino acids identified were aspartic acid, alanine and smaller amounts of 3- and 4-carbon amino acids. This finding as well as the total absence of radioactive glutamic acid substantiates the mechanism for reduction of CO{sub 2} previously postulated by members of this laboratory.
Date: May 25, 1948
Creator: Stepka, W.; Benson, A. A. & Calvin, M.
Object Type: Report
System: The UNT Digital Library
Path of Carbon in Photosynthesis III (open access)

Path of Carbon in Photosynthesis III

Although the overall reaction of photosynthesis can be specified with some degree of certainty (CO{sub 2} + H{sub 2}O + light {yields} sugars + possibly other reduced substances), the intermediates through which the carbon passes during the course of this reduction have, until now, been largely a matter of conjecture. The availability of isotopic carbon, that is, a method of labeling the carbon dioxide, provides the possibility of some very direct experiments designed to recognize these intermediates and, perhaps, help to understand the complex sequence and interplay of reactions which must constitute the photochemical process itself. The general design of such experiments is an obvious one, namely the exposure of the green plant to radioactive carbon dioxide and light under a variety of conditions and for continually decreasing lengths of time, followed by the identification of the compounds into which the radioactive carbon is incorporated under each condition and time period. From such data it is clear that in principle, at least, it should be possible to establish the sequence of compounds in time through which the carbon passes on its path from carbon dioxide to the final products. In the course of shortening the photosynthetic times, one times, one …
Date: June 1, 1948
Creator: Benson, A. A. & Calvin, M.
Object Type: Report
System: The UNT Digital Library
Monthly Progress Report No. 59 for March 1948 (open access)

Monthly Progress Report No. 59 for March 1948

This monthly progress report covers the following programs: (1) 184-inch Cyclotron; (2) 60-inch Cyclotron; (3) Synchrotron; (4) Linear Accelerator; (5) Experimental Physics; (6) Theoretical Physics; (7) Chemistry; (8) Medical Physics; and (9) Health Physics and Chemistry.
Date: March 1, 1948
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Path of Carbon in Photosynthesis IV. The Identity and Sequencefo the Intermediates in Sucrose Synthesis (open access)

The Path of Carbon in Photosynthesis IV. The Identity and Sequencefo the Intermediates in Sucrose Synthesis

The synthesis of sucrose from C{sup 14}0{sub 22} by green algae has been investigated and the intermediates separated by the method of paper chromatography. It is shown that sucrose is the first free sugar appearing during photosynthesis. It is apparently formed by condensation of the glucose-I-phosphate and a fructose phosphate. A series of radioautographs of paper chromatograms of extracts from plants which have photosynthesized for different periods of time has been prepared. The results indicate that 2-phosphoglyceric acid is the first product synthesized from C0{sub 2} during photosynthesis.
Date: December 14, 1948
Creator: Calvin, M. & Benson, A.
Object Type: Report
System: The UNT Digital Library
Production for Mesons by X-rays (open access)

Production for Mesons by X-rays

At the spring, 1949, meeting of the National Academy of Sciences(l) a preliminary account was given of some observations of mesons produced by the 335 Mev x-ray beam from the Berkeley synchrotron. The present paper is a progress report of this work; no claim is made for completeness, but sufficient new data are available to make publication at this time worth while, especially since some of the numerical results given in the earlier report require revision. The x-ray beam, produced by the impact of 335 Mev electrons on a 20 mil thick platinum target, has a width at half maximum of 0.0135 radian (about 1 inch at 6 feet from the target). In all but the earliest experiments the beam was further defined by a 1 inch hole in a lead block, then passed through a piece of carbon which served as the meson source. The x-ray intensity at one meter from the target was about 3500 r per hour (measured behind 1/8 inch of lead) under the best running conditions; the average was about half this. The actual exposures at the carbon meson source (6 feet from the target) ranged from 500 to 2000 r in the later runs. …
Date: September 15, 1949
Creator: McMillan, Edwin M.; Peterson, Jack & White, R. Stephen
Object Type: Report
System: The UNT Digital Library
An Isotope Effect in a Simple Chemical Reaction (open access)

An Isotope Effect in a Simple Chemical Reaction

It has been found that the carbon dioxide obtained from the decarboxylation of singly-carboxyl labeled malonic acid is impoverished in the C{sup 14} label and that the acetic acid formed is correspondingly enriched.
Date: July 13, 1948
Creator: Yankwich, Peter E. & Calvin, Melvin
Object Type: Report
System: The UNT Digital Library
Progress Report No. 65 Aug. 15-Sept. 15, 1948 (open access)

Progress Report No. 65 Aug. 15-Sept. 15, 1948

This is a progress report on the following: (1) 184-inch Cyclotron Program; (2) 60-inch Cyclotron Operation; (3) Synchrotron Program; (4) Linear Accelerator Operation; (5) Experimental Physics; (6) Theoretical Physics; (7) Isotope Separation Program; (8) Chemistry; (9) Medical Physics; and (10) Health Chemistry and Physics.
Date: September 15, 1948
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Diffraction Effects in Neutron Attenuation Measurements (open access)

Diffraction Effects in Neutron Attenuation Measurements

All errors due to diffraction effects in a neutron attenuation experiment are computed. Also a special experiment to measure the forward intensity of diffracted neutrons from lead and copper is described, and the results given. These agree with the theoretical values.
Date: November 1, 1947
Creator: McMillan, E. M. & Sewell, D. C.
Object Type: Report
System: The UNT Digital Library
200 Area monthly reports, July--December 1947 (open access)

200 Area monthly reports, July--December 1947

This document presents the monthly reports of the 200 area technical group for July--December, 1947. (KS)
Date: January 1, 1947
Creator: Stanford, R.E.L. & Christy, J.T.
Object Type: Report
System: The UNT Digital Library
P Division monthly report, November 1948 (open access)

P Division monthly report, November 1948

This progress report discusses activities at the P Division for the month of November 1948. All piles operated at 275 megawatts (MW) throughout the month except for outages listed under Area Activities in this report and except that F Pile operated at a reduced level during the first half of the month. This operation at reduced level was incident to the leaking process tube reported last month. A total of 81.4 tons of metal was discharged from the piles during the month. The 300 Area canned a total of 150 tons of acceptable slugs during the month to establish a new production record. On November 29 the operating schedule for the Melt Plant was changed from a three-shift to a two-shift, six-day week schedule. The backlog of material largely had been worked off and the new schedule is adequate for processing the current accumulation of scrap.
Date: December 20, 1948
Creator: Lee, Edward P.
Object Type: Report
System: The UNT Digital Library
Production of I sup 131 (open access)

Production of I sup 131

We have reviewed the problem of recovering I{sup 131} from the Separations Process and conclude that recovery is entirely feasible. This report contains recommendations for I{sup 131} recovery offered for consideration and are based on a technical study.
Date: April 17, 1946
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Production test 105-2-P (Supplement A) - Activity of pile discharge water (Activation of manganese and iron) (open access)

Production test 105-2-P (Supplement A) - Activity of pile discharge water (Activation of manganese and iron)

This report discusses the Production Test 105-2-P (Supplement A) -- Activity of Pile Discharge Water. Previous studies of pile discharge water have shown that one of two processes is responsible for the large but variable amount of Mn{sup 56} activity present in the water. One process is the production of Mn{sup 56} by the reaction Mn{sup 55} on manganese impurity in the water. The amount of such impurity has been shown to be too small to produce the observed amount of Mn{sup 56} unless the mean irradiation time is increased by a large factor due to temporary sticking of manganese on the surfaces in the tubes. The other process is the production by the reaction Fe{sup 56} on iron in the film. The present production test was designed to determine which of these processes is responsible for the troublesome Mn{sup 56} activity and to what extent the activity is increased due to sticking of manganese or iron in the tubes. 4 figs.
Date: May 8, 1946
Creator: West, J.M.
Object Type: Report
System: The UNT Digital Library
Photographic film as a pocket radiation dosimeter (open access)

Photographic film as a pocket radiation dosimeter

The energy dependence of film blackening is discussed and shown graphically. The exposure range of films is discussed, and blackening is plotted vs exposure for DuPont No. 502, and for the less sensitive DuPont No. 351. A plan is then described for monitoring radiation exposure to workers by requiring the worker to carry an x-ray film of dental packet size in a badge designed for the purpose. (LEW)
Date: April 25, 1944
Creator: Pardue, L. A.; Goldstein, N. & Wollan, E. O.
Object Type: Report
System: The UNT Digital Library
Review of the stack discharge active particle contamination problem (open access)

Review of the stack discharge active particle contamination problem

Quantities of the order of ten million to 100 million radioactive particles per month were emitted from the stacks over a period of several months. High activity in the range 0.1 to 3..mu..c was probably confined to large carrier particles of corrosion debris from iron ductwork in the separations plant ventilation air system. This report discusses chemical, physical and radiochemical properties of the particles, and possible biological and health effects of exposure to them. (ACR)
Date: March 22, 1948
Creator: Parker, H M
Object Type: Report
System: The UNT Digital Library
The trend of contamination in the air, Columbia River, rain, sanitary water, vegetation, and wastes, at the Hanford Works and vicinity for the period October, November, December 1947 (open access)

The trend of contamination in the air, Columbia River, rain, sanitary water, vegetation, and wastes, at the Hanford Works and vicinity for the period October, November, December 1947

This report summarizes the contamination observed at the Hanford Works and vicinity for the period October, November, and December, 1947. Trend charts showing trend of contamination for the various sampling locations are only included where a true trend can be established for the three month period; a thorough analysis of all trends will be considered in detail in the annual report from this section. The report is divided into the following topic sections: Meteorological -- dissolving data; beta contamination in the air and the radiation levels in air; alpha and beta contamination in the Columbia River; beta contamination in the rain and snow; alpha and beta contamination in drinking water; beta contamination on vegetation; and alpha and beta contamination in Hanford Wastes. An appraisal and review of all the results is considered in detail for each section. Statistical analysis is used whenever possible to determine significant values and differences in levels of contamination measured.
Date: March 20, 1948
Creator: Singlevich, W.
Object Type: Report
System: The UNT Digital Library
100-D unit purge (open access)

100-D unit purge

None
Date: August 5, 1945
Creator: Dahlen, P. A.
Object Type: Report
System: The UNT Digital Library
Wind dilution required to reduce to tolerance levels the activity due to xenon and iodine in HEW dissolver off-gases (open access)

Wind dilution required to reduce to tolerance levels the activity due to xenon and iodine in HEW dissolver off-gases

The radio-active xenon and iodine evolved during the dissolution of the uranium may present a health hazard within certain areas around the base of the stack through which the dissolver off-gases are discharged. Since the concentration of these elements in the uranium metal is directly proportional to the power of the pile* and is related to decay period of the metal in accordance with their half-lifes, the maximum rate of discharge of these elements from the stack at H.E.W. can be estimated form existing Clinton data. The required wind dilution to reduce the discharging activation to tolerance levels can then be calculated. The time with respect to the start of the metal dissolution at which the maximum rates of discharge will be attained can also be roughly estimated form existing Clinton data. 3 figs., 3 tabs.
Date: September 29, 1944
Creator: Dreher, J.L.
Object Type: Report
System: The UNT Digital Library
Radioactive contamination in the environs of the Hanford Works for the period January, February, March 1949 (open access)

Radioactive contamination in the environs of the Hanford Works for the period January, February, March 1949

This report summarizes in somewhat more detail than the monthly H.I. Environs reports the extent and magnitude of the radioactive contamination detected in the environs of the Hanford Works. Radioactive contamination resulting from the operation of the Hanford Works as well as that found occurring in natural quantities is included. This belated report is being issued merely for the records to serve as a composite summary of measurements already reported in the monthly H.I. Environs reports and covers the quarterly period January, February, and March, 1949.
Date: December 23, 1949
Creator: Singlevich, W. & Paas, H.J.
Object Type: Report
System: The UNT Digital Library
Exposure history of discharged metal (open access)

Exposure history of discharged metal

None
Date: April 30, 1945
Creator: Menegus, R.L.
Object Type: Report
System: The UNT Digital Library
Cooling water requirements in 212 buildings (open access)

Cooling water requirements in 212 buildings

This document provides plots of expected rates of heat evolution rates of heat evolution from irradiated metal which may be useful in estimating the cooling water flow required in the the 212 buildings. A comparison of three sources of data found in the Project Handbook is provided. The CN 526 calculations agree very well with the estimates of 16, 32 and 64 days decay periods. CN 526 information was used for calculating the heat evolution rates shown in the following figures, since the data does not cover decay periods under 16 days, and does not include the 93{sup 239} contribution. The expected BTU/Min.(Ton) heat liberation rate vs. cooling time in days for through operating periods is shown. The operating level is taken as 2000 KW/Ton; the BTU/Min.(Ton) liberated may be scaled to higher or lower operating levels by arithmetic ratio. A similar curve in which the cooling water required (GPM/Ton) is substituted for BTU/Min.(Ton) is provided. The metric ton and a water temperature rise of 25{degree}C (45{degree}F) are assumed. The product content of the metal has been substituted for operating level in another plot. The rate of heat evolution is plotted against decay period for various operating times. A base …
Date: November 9, 1944
Creator: Peery, L.C.
Object Type: Report
System: The UNT Digital Library
P Division monthly report, September 1949 (open access)

P Division monthly report, September 1949

This progress report discusses the activities of the P Division for the month of September, 1949. The B and F piles operated at 275 megawatts (MW) and the D pile at 305 MW throughout the month except for cutages listed under Area Activities. A total of 60.22 tons of metal, at an average concentration of 396 megawatt days/ton (MWD/ton) was discharged from the piles during the month. The 105-H Building was accepted from the Construction Division on September 28 with certain exceptions noted under the Operating Experience section of this report. At month end P Division operating personnel are making preparations for activation of the H pile. On September 28 the operation of the 300 Area oxide burning process was reduced from a two shift to a one shift five day operation. This change in schedule was possible as a result of working off the backlog of uranium oxide. The shipment of 200 tons of canned slugs to Building 105-DR for storage was completed on September 9 and the shipment of 250 tons of canned slugs to Building 105-H for the initial loading charge was completed on September 26.
Date: October 6, 1949
Creator: Lee, Edward P.
Object Type: Report
System: The UNT Digital Library