Rutherford (unit)

Last updated
rutherford
Unit of Activity
SymbolRd
Named after Lord Ernest Rutherford
Conversions
1 Rd in ...... is equal to ...
    curie    2.703×10−5 Ci
    SI derived units    1  MBq
    SI base units    106  s −1

The rutherford (symbol Rd) is a non-SI unit of radioactive decay. It is defined as the activity of a quantity of radioactive material in which one million nuclei decay per second. It is therefore equivalent to one megabecquerel, and one becquerel equals one microrutherford. One rutherford is equivalent to 2.702×10−5 curie, or 37000 rutherfords for one curie.

The unit was introduced in 1946. [1] It was named after British/New Zealand physicist and Nobel laureate Lord Ernest Rutherford (Nobel Prize in 1908), [2] who was an early leader in the study of atomic nucleus disintegrations. After the becquerel was introduced in 1975 [3] as the SI unit for activity, the rutherford became obsolete, and it is no longer commonly used.

The following table shows radiation quantities in SI and non-SI units:

Ionizing radiation related quantities
QuantityUnitSymbolDerivationYear SI equivalent
Activity (A) becquerel Bqs−11974SI unit
curie Ci3.7×1010 s−119533.7×1010 Bq
rutherford Rd106 s−119461000000 Bq
Exposure (X) coulomb per kilogram C/kgC⋅kg−1 of air1974SI unit
röntgen R esu / 0.001293 g of air19282.58×10−4 C/kg
Absorbed dose (D) gray Gy J⋅kg−11974SI unit
erg per gramerg/gerg⋅g−119501.0×10−4 Gy
rad rad100 erg⋅g−119530.010 Gy
Equivalent dose (H) sievert SvJ⋅kg−1 × WR 1977SI unit
röntgen equivalent man rem100 erg⋅g−1 × WR 19710.010 Sv
Effective dose (E) sievert SvJ⋅kg−1 × WR × WT 1977SI unit
röntgen equivalent man rem100 erg⋅g−1 × WR × WT 19710.010 Sv


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References

  1. Lind, SC (1946), "New units for the measurement of radioactivity", Science, 103 (2687): 761–762, Bibcode:1946Sci...103..761L, doi:10.1126/science.103.2687.761-a, PMID   17836457, S2CID   5343688.
  2. "The Nobel Prize in Chemistry 1908".
  3. Harder, D (1976), "[The new radiologic units of measurement gray and becquerel (author's translation from the German original)]", Röntgen-Blätter, 29 (1): 49–52, PMID   1251122.