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Nuclear Data Sheets for A = 210

Evaluated spectroscopic data for {sup 210}Au, {sup 210}Hg, {sup 210}Tl, {sup 210}Pb, {sup 210}Bi, {sup 210}Po, {sup 210}At, {sup 210}Rn, {sup 210}Fr, {sup 210}Ra, {sup 210}Ac, and {sup 210}Th and corresponding level schemes from radioactive decay and reaction studies are presented. This evaluation supersedes the previous evaluation by E. Browne (2003Br13). Highlights of this publication are the identification of new μs isomers of {sup 210}Hg by 2013Go10 and measurement of an excited level energy at 1709 keV 30 of {sup 210}Rn from {sup 214}Rn α decay: 68.6 μs by 2006Ku26 denoted as x+1664.6 in the Adopted Levels. Earlier experimental limits for x≤50 keV was proposed in 1979Po19 and 1982Po03 – (HI,xnγ)

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Uptake behavior of 73 As, 75 Se, 197m Hg, 212 Pb and 210 Po on Eichrom pre-filter resin from HCl and HNO 3

We report the extraction of 73 As, 75 Se, 197 mHg, 212 Pb and 210 Po on Eichrom pre-filter resin was studied in HCl and HNO 3 with batch uptake, kinetic and column experiments. There was significant extraction of mercury in HNO 3 and HCl, and polonium and selenium in HCl. The kinetics are sufficient to allow for retention on pre-filter columns, and separations of 73 As from 75 Se and 197 mHg, and 212 Pb from 210 Po are demonstrated. This retention is important for the development of chemical separations as pre-filter resin is commonly used alongside extraction chromatography resins but its potential for uptake of metal ions is not well characterized.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Modeling of the Magnetosphere of Mercury at the Time of the First MESSENGER Flyby

The MESSENGER spacecraft flyby of Mercury on 14 January 2008 provided a new opportunity to study the intrinsic magnetic field of the innermost planet and its interaction with the solar wind, The model presented in this paper is based on the solution of the three-dimensional, bi-f1uid equations for solar wind protons and electrons in the absence of mass loading, In this study we provide new estimates of Mercury's intrinsic magnetic field and the solar wind conditions that prevailed at the time of the flyby. We show that the location of the boundary layers and the strength of the magnetic field along the spacecraft trajectory can be reproduced with a solar wind ram pressure P(sub sw) = 6.8 nPa and a planetary magnetic dipole having a magnitude of 210 R(sub M)(exp 3)- nT and an offset of 0.18 R(sub M) to the north of the equator, where R(sub M) is Mercury's radius. Analysis of the plasma flow reveals the existence of a stable drift belt around the planet; such a belt can account for the locations of diamagnetic decreases observed by the MESSENGER Magnetometer. Moreover, we determine that the ion impact rate at the n011hern cusp was four times higher than at the southern cusp, a result that provides a possible explanation for the observed north-south asymmetry in exospheric sodium in the neutral tail.

Benna, Mehdi↗

Investigation of High-Performance Fuels in Multicylinder and in Single-Cylinder Engines at High and Cruising Engine Speeds

An investigation was conducted to compare the knock-limited performance of a 20-percent triptane blend in 28-K fuel with that of 28-R and 33-R fuels at high engine speeds, cruising speeds, and two compression ratios in an K-1830-94 multicylinder engine, Data were obtained with the standard compression ratio of 6.7 and with a compression ratio of 3.0, The three fuels were investigated at engine speeds of 1800, 2250, 2600, and 2800 rpm at high and low blower ratios. A carburetor-air temperature of approximate1y 100 deg F was maintained for the multicylinder-engine runs, Data were obtained on a single R-1830-94 cylinder engine as a means of checking the multicylinder data at the higher speeds. A satisfactory correlation between average mixture temperature and knock-limited manifold pressure was obtained by plotting knock-limited manifold pressure against average mixture temperature for the whole range of engine speeds at constant carburetor air temperature and cylinder-head temperature. The single-cylinder knock-limited performance based on charge-air flow matched that of the multicylinder engine within 6 percent under all the conditions except for 28-R fuel at 2800 rpm; these curves differed from each other by 11 percent in the rich region. The knock rating of 33-R fuel was found to be a little higher than that of the 20-percent triptane blend and 26-R fuel at high mixture temperatures (above 210 deg F) and lean mixtures. The 33-R fuel exhibited rich knock limits appreciably lower than the 20-percent triptane blend, Increasing the compression ratio from 6.7 to 8.0 lowered the knock-limited manifold pressure for all fuels approximately 15 to 18 inches of mercury absolute in the cruising range and 20 to 28 inches of mercury absolute at higher engine speeds. Brake specific fuel consumption was reduced 7 to 9 percent by the increase in compression ratio from 6.7 to 8,0,

Bell, Arthur H.↗

Geochemistry at 4 Vesta: Observations Using Fast Neutrons

Dawn is currently in orbit around the asteroid 4 Vesta, and one of the major objectives of the mission is to probe the relationship of Vesta to the Howardite, Eucrite, and Diogenite (HED) meteorites. As Vesta is an example of a differentiated planetary embryo, Dawn will also provide fundamental information about planetary evolution in the early solar system [1]. To help accomplish this overall goal, the Dawn spacecraft carries the Gamma-Ray and Neutron Detector (GRaND). GRaND uses planetary gamma-ray and neutron spectroscopy to measure the surface elemental composition of Vesta and will provide information that is unique and complementary to that provided by the other Dawn instruments and investigations. Gamma-ray and neutron spectroscopy is a standard technique for measuring planetary compositions [2], having successfully made measurements at near-Earth asteroids, the Moon, Mars, Mercury and now Vesta. GRaND has made the first measurements of the neutron spectrum from any asteroid (previous asteroid measurements were only made with gamma-rays). Dawn has been collecting data at Vesta since July 2011. The prime data collection period for GRaND is the Low-Altitude Mapping Orbit (LAMO), which started on 12 December 2011 and will last through spring 2012. During LAMO, the Dawn spacecraft orbits at an average altitude of ~210 km above the surface of Vesta, which allows good neutron and gamma-ray signals to be detected from Vesta. A description of the overall goals of GRaND and a summary of the initial findings are given elsewhere [3,4]. The subject of this study is to present the information that will be returned from GRaND using fast neutron measurements. Here, we discuss what fast neutrons can reveal about Vesta s surface composition, how such data can address Dawn science goals, and describe fast neutron measurements made in the early portion of the Vesta LAMO phase.

Lawrence, David J.↗

Application of Nuclear Technology to Art Identification Problems: First Annual Report

Throughout the centuries, as man has become increasingly affluent, his interest in antiquities and objects of art, and the price he has been willing to pay for them, has increased. Inevitably, one result has been to attract the unscrupulous to the production and sale of counterfeit paintings, sculptures, and other works of art. The skill of forgers varies but often is highly sophisticated. However, dealers, museum curators, and other experts have also become more skillful in the detection of forgeries. Scientific tools of increasing sensitivity and sophistication have gradually been applied to the examination of the materials of art and archaeology. Such tools frequently support and render more reliable the judgment of the experts. The quality of forgeries may improve further as their makers become acquainted with the new methods of detection and in turn learn to circumvent or confound the methods. Therefore, the development of still more advanced methods of examination has great utility in the art world. This is particularly true if the ultimate effect is to make circumvention of the methods of examination so costly that the economic incentives for producing forgeries may be substantially reduced, if not eliminated.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

The measurement of radiation exposure of astronauts by radiochemical techniques

Cosmic radiation doses to the crews of the Apollo 14, 15, and 16 missions of 142 + or - 80, 340 + or - 80, and 210 + or - 130 mR respectively were calculated from the specific activities of Na-22 and Na-24 in the postflight urine specimens of the astronauts. The specific activity of Fe-59 was higher in the urine than in the feces of the Apollo 14 and 15 astronauts, and a possible explanation is given. The concentrations of K-40, K-42, Cr-51, Co-60, and Cs-137 in the urine are also reported for these astronauts. The radiation doses received by pilots and navigators flying high altitude missions during the solar flare of March 27 to 30, 1972 were calculated from the specific activity of Na-24 in their urine. These values are compared with the expected radiation dose calculated from the known shape and intensity of the proton spectrum and demonstrate the magnitude of atmospheric shielding. The concentrations of Na, K, Rb, Cs, Fe, Co, Ag, Zn, Hg, As, Sb, Se, and Br were measured in the urine specimens from the Apollo 14 and 15 astronauts by neutron activation analysis. The mercury and arsenic levels were much higher than expected.

Brodzinski, R. L.↗