The uncertainty in the positron counts are huge at the high energy end of the AMS-02 results.
Another highly regarded method was PET, or positron emission tomography.
1933, coined from posi(tive) (elec)tron.
positron pos·i·tron (pŏz'ĭ-trŏn')
A positively charged particle of the same mass and magnititude of charge as an electron. Also called antielectron, positive electron.