reb and rem

[FRAMEP@ORAU.GOV]

The following is long and boring, but there is a nice story at the end - one
that Ron Kathren kindly left for me to repeat.

As Ron mentioned, first there was the roentgen (abbreviated into the 60s
with a small r rather than the capital R used today). For what its worth
the curie was abbreviated as "c" until the early 60s.

Then in the 1940s Herb Parker introduced  the rep (which the ICRU
changed in 1953 into the rad) and the reb (which he himself changed into
the rem).

The rep, reb, rem , and rad were chosen because they began with r,
were short, and easy to pronounce.

In his report of Nov 1955 to the Commission on Radiologic Units,
Standards and Protection,  Herb Parker (speaking in the third person)
notes:    "In the atomic energy program beginning in 1942, one was faced
with the practical problem of adding the doses received by a large group
of workers from quantum radiation, alpha , beta and neutron radiation.
Parker was led to a coterie system that had to be readily communicable.
He used rep as an equivalent roentgen, based originally on X=83
[ergs/gram] but changed to x=93 and rem as a biological unit obtained by
multiplying the components of the dose in rep by appropriate RBE
multipliers."

In the above mentioned report, he cites his paper  "Tentative Dose Units
for Mixed Radiations" Radiology 54:257-260, 1950. which Ron also spoke
of.