Convert Curies to Femtobecquerels

Convert Curies (Ci) to Femtobecquerels (fBq) instantly and accurately.

Curies (Ci)
Femtobecquerels (fBq)

Conversion Formula

fBq = Ci × 3.700000000e+25

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 Femtobecquerels

The femtobecquerel (fBq) equals 10⁻¹⁵ Bq, used in accelerator mass spectrometry (AMS) to quantify cosmogenic radionuclides (¹⁰Be, ³⁶Cl) in ice cores and geological samples. Ultra-low-background counting in deep underground laboratories reaches the fBq/kg level for solar neutrino detector purity assessment. 1 fBq = 10⁻¹⁵ Bq = 10⁻³ pBq.

Quick Reference Table

Curies (Ci)Femtobecquerels (fBq)
1 Ci3.7 × 1025 fBq
2 Ci7.4 × 1025 fBq
5 Ci1.85 × 1026 fBq
10 Ci3.7 × 1026 fBq
25 Ci9.25 × 1026 fBq
50 Ci1.85 × 1027 fBq
100 Ci3.7 × 1027 fBq

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