Curium-248 in the Early Solar System

  title={Curium-248 in the Early Solar System},
  author={M. R. Rao and K. Gopalan},
PRIMITIVE meteorites such as carbonaceous chondrites (CC) and unequilibrated ordinary chondrites (UOC) have an anomalous fission xenon component1–3 which has a distinctly different fission spectrum from that of Ca-rich achondrites4,5. Although the latter is established as due to 244Pu spontaneous fission4, the origin of the former component is still debated. Further, the amount of fission xenon present in CC II–IV and some UOC is about two orders of magnitude6,7 higher than that of Ca-rich… Expand
17 Citations
Elimination of 248Cm as a possible progenitor of carbonaceous chondrite fission xenon
It has been suggested by various authors that spontaneous fission of 248Cm may be responsible, at least in part, for the heavy-isotope anomalies, known as the CCF component, in xenon extracted fromExpand
On possible short-lived progenitors of fission xenon in carbonaceous chondrites
We suggest that the unidentified fission xenon component in carbonaceous chondrites may be attributable to the decay of the extinct radioactivities250Cm and, to a lesser extent,258Cm. Two assumptionsExpand
Isotopic anomalies of noble gases in meteorites and their origins—III. LL-chondrites
Nine LL-chondrites were studied by a selective etching technique, to characterize the noblegas components in three mineral fractions: HF-HCl-solubles (silicates, metal, troilite, etc.; comprising ∼Expand
Extinct Superheavy Element in the Allende Meteorite
An effort has been made to identify the extinct superheavy element that was present in meteorites and decayed to 131-136Xe by spontaneous fission. To characterize its chemical properties, we haveExpand
Search for 248Cm in the early Solar System
— Possible evidence for the presence of 248Cm in the early Solar System was reported from fission gas studies (Rao and Gopalan, 1973) and recently from studies of very high nuclear track densities (≥Expand
Solar system isotopic anomalies: Supernova neighbor or presolar carriers?
Abstract I evaluate several nuclear and chemical problems related both to the recent scenario suggesting that the known isotopic anomalies in the solar system have resulted from a supernova near theExpand
Host phases and origin of noble gases in meteorites
A large fraction of the noble gases in carbonaceous chondrites are concentrated in a small amount of meteoritic matter (≲ 2%). It consists of carbon (in different forms) and chromite which are theExpand
Isotopic anomalies in meteorites
The classical picture of the pre-solar nebula is that of a hot, well-mixed cloud of chemically and isotopically uniform composition. Recent measurements have shown this conception to be erroneous,Expand
Kr and Xe isotopes from spontaneous fission of 248Cm and 250Cf: Comparison with noble gases in carbonaceous chondrites
Abstract Relative yields of Kr and Xe isotopes from the spontaneous fission of 248 Cm and 250 Cf have been determined mass spectrometrically. The yields are as follows: 83 Kr/ 84 Kr/ 85 Kr/ 86 Kr =Expand
Noble gases in D’Orbigny, Sahara 99555 and D’Orbigny glass—Evidence for early planetary processing on the angrite parent body
Abstract We analyzed the spallogenic, trapped, fissiogenic and radiogenic noble gas components in various bulk samples of the angrites D’Orbigny and Sahara 99555 as well as in glass separates ofExpand


Neon and Xenon in Carbonaceous Chondrites
Abstract Current evidence indicates that trapped meteoritic neon and xenon are complex mixtures of independent components from different sources. A particularly strong case can now be made for theExpand
Correlation between fission tracks and fission type xenon in meteoritic Whitlockite
Whitlockite from the St. Severin chondrite, previously shown to contain excess fission tracks, is here shown to have a large concentration of excess neutron-rich xenon isotopes. The concentration ofExpand
129I and244Pu abundances in white inclusions of the Allende meteorite
Abstract Data are presented for thermal-release xenon analysis of a neutron-irradiated sample of white inclusions from the carbonaceous chondrite Allende. The best-fit high-temperature 129 Xe/ 132 XeExpand
On the origin of excess heavy xenon in primitive chondrites
Abstract In heating experiments, xenon was studied in separated matrix and chondrule samples of the Mokoia carbonaceous chondrite and the Chainpur unequilibrated ordinary chondrite. Larger isotopicExpand
IXe dating: Evidence for cold assembly of an unequilibrated chondrite
Abstract Essentially all of the more equilibrated meteorites which contain excess radiogenic 129 Xe have well-defined I Xe formation intervals that apparently date the onset of proportional retentionExpand
Iodine-129/Xenon-129 Age of Magnetite from the Orgueil Meteorite
If Karoonda and Orgueil magnetite formed from similar material, then the age difference is an upper limit to the formation time of these meteorites—and by customary extension, the solar system. Expand
A detailed analysis of the rare gas content of the chondrite Renazzo is presented. Fractions of different isotopic composition are separated by heating the sample to successively higher temperatures.Expand
Plutonium-244: Confirmation as an Extinct Radioactivity
The mass spectrum of xenon from spontaneous fission in a laboratory sample of plutonium-244 is precisely what meteoriticists predicted it would be, and the search for an explanation for anomalous fission-like xenon in carbonaceous chondrites can now be narrowed. Expand
Spallation and fissiogenic xenon and krypton from stepwise heating of the Pasamonte achondrite; The case for extinct plutonium 244 in meteorites; Relative ages of chondrites and achondrites
Following the discovery by Rowe and Kuroda that there are striking excesses of the xenon ratios 134/132 and 136/132 in the Pasamonte achondrite, we performed stepwise heating experiments with thisExpand
Ages of the Allende meteorite
Abstract The rare gases and the K and U were measured in whole-rock and chondrule samples of the Allende meteorite, a type-3 carbonaceous chondrite. There is an enrichment of the He4, Ar40, K, and U,Expand