kBq

The kilobecquerel (kBq) is the unit of radioactivity in the International System of Units (SI), used to express the rate of radioactive decay. It is a multiple of the becquerel (Bq), with 1 kBq equal to 1,000 Bq. Since a becquerel represents one decay per second, a kilobecquerel represents 1,000 decays per second.

Conversions and context: 1 Bq = 1 s^-1, 1 kBq = 1 × 10^3 Bq, and 1 MBq = 1 × 10^6 Bq. In practical terms, kBq is used for activities that are larger than a few Bq but smaller than those typically expressed in MBq. The curie (Ci) is a non-SI unit sometimes encountered in older literature, with 1 Ci ≈ 3.7 × 10^10 Bq (about 37,000,000 kBq).

Applications and usage: kBq is commonly used in nuclear medicine, radiopharmacology, environmental radiology, and radiological safety to describe the activity of sources, samples, or dosimetry calculations. In clinical settings, radiopharmaceutical doses are often reported in MBq, while surface contamination and certain environmental measurements may be presented in Bq or kBq. Instrumental readings in counts per second or disintegrations per minute are typically converted to activity units (Bq, kBq, or MBq) after correcting for detector efficiency and geometry.