Convert Curies to Rutherfords

Convert Curies (Ci) to Rutherfords (Rd) instantly and accurately.

Curies (Ci)
Rutherfords (Rd)

Conversion Formula

Rd = Ci × 37000

About Curies

The curie (Ci) equals exactly 3.7 × 10¹⁰ Bq = 37 GBq, originally defined as the activity of 1 g of ²²⁶Ra. Still widely used in the US: ⁶⁰Co teletherapy sources are 5000-15000 Ci; ¹³⁷Cs blood irradiators are 1000-40000 Ci; NRC source licences for industrial radiography cite Ci limits. 1 Ci = 3.7 × 10¹⁰ Bq.

About Rutherfords

The rutherford (Rd) equals exactly 10⁶ Bq = 1 MBq. Proposed by Ernest Rutherford and adopted at the 1946 Montreal Conference on Radioactivity as a convenient unit for large sources. Superseded by the MBq in SI but still encountered in older nuclear physics and reactor engineering literature. 1 Rd = 10⁶ Bq.

Quick Reference Table

Curies (Ci)Rutherfords (Rd)
1 Ci37000 Rd
2 Ci74000 Rd
5 Ci185000 Rd
10 Ci370000 Rd
25 Ci925000 Rd
50 Ci1850000 Rd
100 Ci3700000 Rd

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