The equivalent dose in an organ or tissue is given by:
[math] H_T = \displaystyle \sum_{R} w_RD_{R,T} [/math]
where DR,T is the mean absorbed dose from radiation R in a tissue or organ T, and wR is the radiation weighting factor. The SI unit of equivalent dose is joule per kilogram (J/kg-1), and its special name is sievert (Sv). (ICRP Publication 123, 2013)
ICRP Glossary entry - May 2019