Oliver Manuel

The Xenon Record of Extinct Radioactivities in the Earth

Analyses of xenon from well gas rich in carbon dioxide reveal a large excess of radiogenic xenon-129 from the decay of extinct iodine-129. Smaller excesses observed in the heavy xenon isotopes are from fission. These results place narrow limits on any age difference between the earth and the oldest meteorites. The occurrence of excess radiogenic xenon-129 in well gas also suggests that any quantitative degassing of existing solid materials to form the atmosphere must have been limited to a very early period of the earths history, approximately the first 108 years. Alternatively, this observation is consistent with a model of the earths continuous, but still incomplete, degassing since its time of formation.

Geochemical measurements of double-beta decay

A review of recent geochemical measurements on the double-beta decay of 82Se, 128Te and 130Te suggests that the current best value for the decay rate of 128Te relative to that of 130Te is 4*10-4 and the current best values for individual half-lives are as follows: 1*1020 y for 82Se, 2*1024 y for 128Te, and 8*1020 y for 130Te.

Noble gases in the Fayetteville meteorite

Abstract Noble gases were extracted from the dark portions of Fayetteville by heating the sample to successively higher temperatures up to 1600°C. Analyses of the neon evolved at each temperature indicate that this gas is a mixture of at least three components. It is shown that the isotopic composition of neon observed could be produced from a mixture of primordial neon, cosmogenic neon, and highly mass-fractionated primordial neon. The isotopic composition of helium, neon and argon indicate a primordial component for which He 3 : He 4 ≤ 0.00031, Ar 38 : Ar 36 ≤ 0.177, Ne 20 : Ne 22 ≥ 12.6, and Ne 21 : Ne 22 ≥ 0.033. The xenon spectra show an excess of the heavy xenon isotopes with a mass yield curve intermediate between that observed in Pasamonte and that in the earths atmosphere. It is shown that this atmosphere-like xenon component is not due to contamination but is definitely a component of meteoritic xenon.

Xenon in Kirkland Lake Tellurides

Measurements on xenon and tellurium from a Kirkland Lake telluride show that the half-life for the double betadecay of 130 Te is 2.03 ± 0.30 × 10 21 years and that of 128 Te is ≧ 1.2 × 10 23 years. It is shown that the excess 129 Xe and 131 Xe in tellurium ores does not correlate with the 130 Te· 130 Xe age or with the uranium content.

Xenon Isotopes in Tellurobismuthite, Boliden, Sweden

Abstract The isotopic composition of xenon is reported in four different samples of tellurobismuthite, Boliden, Sweden, of varying tellurium content. It is observed that excess 129 Xe, 130 Xe and 131 Xe, vary proportionately to the tellurium content of the sample. From the excess 130 Xe measurement, the half-life for double beta decay of 130 Te is calculated to be 2·51 × 10 21 yr. From the observed excess of 128 Xe in the most tellurium rich sample, the half-life for the double beta decay of 128 Te is estimated to be greater than 2·7 × 10 23 yr. It is shown that solar neutrino induced reactions on 128 Te and 130 Te do not contribute significantly to the observed excesses of 128 Xe and 130 Xe. The isotopic composition of xenon in a pyrite sample from the Boliden mine and in two samples of the cesium-rich mineral, pollucite, are used to examine previous hypotheses for the origin of excess 129 Xe and 131 Xe in tellurium ores. It is shown that these two xenon isotopes are produced in situ by nuclear reactions on tellurium.

The Sun Kings: The Unexpected Tragedy of Richard Carrington and the Tale of How Modern Astronomy Began

List of Illustrations ix Acknowledgments xi Prologue: The Dog Years 1 Chapter One: The First Swallow of Summer 9 Chapter Two: Herschels Grand Absurdity 25 Chapter Three: The Magnetic Crusade 47 Chapter Four: The Solar Lockstep 58 Chapter Five: The Day and Night Observatory 71 Chapter Six: The Perfect Solar Storm 80 Chapter Seven: In the Grip of the Sun 93 Chapter Eight: The Greatest Prize of All 98 Chapter Nine: Death at the Devils Jumps 117 Chapter Ten: The Suns Librarian 129 Chapter Eleven: New Flare, New Storm, New Understanding 148 Chapter Twelve: The Waiting Game 168 Chapter Thirteen: The Cloud Chamber 179 Epilogue: Magnetar Spring 188 Bibliography 191 Index 207

Origin of Elements in the Solar System

The solar system is chemically and isotopically heterogeneous. The earth contains only 0.0003% of the mass of the solar system, but the abundance pattern of non-radiogenic isotopes for each terrestrial element has been defined as “normal”.

Iodine-129 in Terrestrial Ores

Xenon extracted from natural iodyrite (silver iodide) from Broken Hill, New South Wales, Australia, contains excess xenon-129 from the in situ decay of naturally occurring iodine-129 and excess xenon-128 from neutron capture on iodine-127. On the basis of the amount of radiogenic xenon-129, it is estimated that, prior to the nuclear age, terrestrial iodine contained an equilibrium ratio of iodine-129 to iodine-127 of between 3.3 x 10-15 and 2.2 x 10-15.

129I−129Xe dating of chondrites

Abstract The 129 I− 129 Xe formation intervals of the Bjurbole, Bruderheim, Bruderheim chondrules, Renazzo, and the dark and light regions of Pantar are calculated by comparing the amount of radiogenic 129 Xe associated with iodine in each thermal fraction. Unlike the sharp 129 I− 129 Xe isochronism reported for the high-temperature minerals, the lower-temperature minerals show progressively longer formation intervals. A plot of formation times versus extraction temperatures yields an apparent 129 I− 129 Xe cooling rate for these chondrites. Below 800°C all of the chondrites except Renazzo and Pantar Dark display 129 I− 129 Xe cooling rates of 5–9°C per million years. Pantar Dark and Renazzo appear to have cooled rapidly to 600° and 400°C, respectively. An inversion of the I−Xe correlation of chondrites is noted in the slow temperature minerals of Shallowater. This enstatite achondrite displays a maximum 129 I− 129 Xe cooling rate of 2.4°C per million years.

STRANGE XENON IN JUPITER

Jupiters helium-rich atmosphere contains xenon with excess136Xe and the ratio of r-products more closely resembles “strange” xenon (Xe-X, alias Xe-HL) seen in carbonaceous chondrites than xenon seen in the solar wind (SW-Xe). The linkage of primordial helium with Xe-X, as seen on a microscopic scale in meteorites, apparently extended across planetary distances in the solar nebula, This is expected if the solar system acquired its present chemical and isotopic diversity directly from debris of the star that produced our elements.