Trace radioisotope

{{Short description|Radioisotope that occurs naturally in trace amounts}}

{{use dmy dates |date=July 2022}}

A trace radioisotope is a radioisotope that occurs naturally in trace amounts (i.e. extremely small). Generally speaking, trace radioisotopes have half-lives that are short in comparison with the age of the Earth, since primordial nuclides tend to occur in larger than trace amounts. Trace radioisotopes are therefore present only because they are continually produced on Earth by natural processes. Natural processes which produce trace radioisotopes include cosmic ray bombardment of stable nuclides, ordinary alpha and beta decay of the long-lived heavy nuclides, thorium-232, uranium-238, and uranium-235, spontaneous fission of uranium-238, and nuclear transmutation reactions induced by natural radioactivity, such as the production of plutonium-239

{{cite journal

| journal = Geochimica et Cosmochimica Acta

| volume = 63 | issue = 2 | pages = 275–285

| year = 1999

| doi = 10.1016/S0016-7037(98)00282-8

| title = Nature's uncommon elements: plutonium and technetium

| first1 = David

| last1 = Curtis

| last2= Fabryka-Martin|first2=June|last3=Paul|first3=Dixon|last4=Cramer|first4=Jan

| bibcode=1999GeCoA..63..275C

| url = https://digital.library.unt.edu/ark:/67531/metadc704244/ }} and uranium-236{{cite web |url=http://esarda2.jrc.it/references/Technical_sheets/ts-mass-spectrometry-071212.pdf |title=Technical sheet about (nuclear) mass spectrometry |access-date=2009-08-28 |url-status=dead |archive-url=https://web.archive.org/web/20110722040435/http://esarda2.jrc.it/references/Technical_sheets/ts-mass-spectrometry-071212.pdf |archive-date=2011-07-22 }} from neutron capture

{{cite journal

| journal = Nuclear Instruments and Methods in Physics Research B

| volume = 259 | issue = 1 | pages = 727–732

|date=June 2007

| doi = 10.1016/j.nimb.2007.01.210

| title = AMS of natural ²³⁶ U and ²³⁹Pu produced in uranium ores

| first1 = K.~M.

| last1 = Wilcken

| last2= Barrows|first2=T. T.|last3=Fifield|first3=L. K.|last4=Tims|first4=S. G.|last5=Steier|first5=P.

|bibcode = 2007NIMPB.259..727W |hdl= 1885/29151| s2cid = 96531059 |hdl-access= free}}

by natural uranium.