I pulled this article off of the HPS web site: Note: The complete article also can be found on the ORAU Web site, and I have edited it so it will fit here on Nukeworker
Why Did They Call It That?
Paul Frame
The Origin of Selected Radiological and Nuclear Terms
Alpha, Beta, and Gamma Radiation
The first reference in the scientific literature to alpha and beta radiation is found in the following statement by Ernest Rutherford (1899): "These experiments show that the uranium radiation is complex and that there are present at least two distinct types of radiation—one that is very readily absorbed, which will be termed for convenience the alpha-radiation, and the other of more penetrative character which will be termed the beta-radiation.
The physicist and historian Alfred Romer (1960) commented that the name alpha radiation had been chosen for "no particular reason." While it is true that Rutherford didn't explain why he chose the first letters of the Greek alphabet, Röntgen had set a precedent for an alphabetical designation with the name X rays, and Rutherford, like many of his generation, had studied the Greek language. In 1902, Rutherford moved on to the third letter of the Greek alphabet when he applied the name gamma rays to the very penetrating radiation described by Villard. Soon thereafter, J.J. Thompson employed the term delta rays, and today we have a veritable alphabet soup of subatomic particles.
Becquerel (Bq)
The SI special name for a unit of activity equal to 1 dps, the becquerel superceded the curie.
In a letter sent to numerous journals in August of 1975, the International Commission on Radiation Units and Measurements (ICRU) stated that the General Conference of Weights and Measures had adopted the ICRU's recommendation that the SI unit of activity take the name the becquerel. The ICRU explained, "Antoine Henri Becquerel (1852-1908) discovered radioactivity in 1896 (‘rayons de Becquerel') and was given the Nobel Prize in Physics in 1903 together with Marie and Pierre Curie." Since the Curies and Becquerel shared the first Nobel Prize awarded for work with radioactive substances, it might be considered appropriate that it was the becquerel that superceded the curie.
Curie (Ci)
A unit of activity equal to 3.7×1010 disintegrations per second, the curie has been superceded by the becquerel.
The original intent of the Standards Committee that defined the curie was for it to be based on a smaller activity, similar to that routinely employed in the laboratory. But Marie Curie had other ideas. If it was to bear the name Curie, it had to be large (Badash 1969)!
In the October 1910 issue of Nature, Ernest Rutherford, who chaired the Standards Committee, said: "In the course of the Congress it was suggested that the name Curie, in honor of the late Prof. [Pierre] Curie, should if be possible, be employed for a quantity of radium or the emanation [radon]. This matter was left for the consideration of the standards committee. The latter suggested that the name Curie be used as a new unit to express the quantity or mass of radium emanation in equilibrium with one gram of radium (element)."
Fission
In late 1938, Lise Meitner and Otto Frisch determined that it was energetically possible for uranium atoms to split in two when struck by neutrons. To observe this phenomenon, Frisch, working in the basement of Niels Bohr's Institute for Theoretical Physics in Copenhagen, placed a piece of uranium next to the chamber of a proportional counter and exposed the uranium to neutrons. Using an oscilloscope, Frisch looked for the extremely large pulses coming from the detector chamber that would indicate the energetic fragments of the splitting atoms. Among the inhabitants of the Institute who went down to the basement to see what Frisch was up to was the biologist William Arnold (Arnold 1996; Ermanc 1989). At first, all Arnold saw on the oscilloscope screen was a series of small pulses produced by uranium's alpha particles. But then, at Frisch's suggestion, he picked up a neutron source by the handle and put it next to the uranium. The world changed! Huge pulses began appearing—pulses far larger than anything produced by the alpha particles—pulses produced by the fragments of the splitting uranium nuclei! Later that day, Frisch tracked Arnold down and said something to the effect "You're supposed to be some kind of biologist. What is the term you use to describe dividing bacteria?" Arnold replied, "Binary fission." Frisch then asked if the word "fission" would suffice and Arnold agreed that it would.
Gray (Gy)
The SI special name for the unit of absorbed dose, equal to 1 J kg-1, the gray superceded the rad.
In a letter sent to numerous journals in August of 1975, the International Commission on Radiation Units and Measurements (ICRU) stated that the General Conference of Weights and Measures had adopted the ICRU's recommendation that the SI unit of absorbed dose take the name the gray. In an explanatory note, the ICRU commented, "Louis Harold Gray (1905-1965) made one of the most fundamental contributions to radiation dosimetry, the principle now known as the Bragg-Gray Principle." It didn't hurt that Gray had once served as Vice-Chairman of the ICRU.
Health Physics
Health Physics refers to the field of radiation protection. Appropriateness of the name has been a matter of some debate (Taylor 1982).
The term Health Physics originated in the Metallurgical Laboratory at the University of Chicago in 1942, but it is not known exactly why, or by whom, the term was chosen. Most likely, the term was coined by Robert Stone or Arthur Compton. Stone was the head of the Health Division, of which Health Physics was one of four sections. Arthur Compton was the head of the Metallurgical Laboratory.
Rad
A unit of absorbed dose, the rad replaced the rep but it has now been superceded by the gray. The name rad was adopted by the ICRU in 1953 at the Seventh International Congress of Radiology. There appears to have been no documented discussion regarding the use of this name prior to the 1953 meeting, even though it was determined earlier at an ICRU meeting in 1951 that there was a need for such a unit. Aside from the use of rad some three decades earlier as a unit relating to mouse tumors, the rad seems to have made its first appearance in the ICRU report of the 1953 meeting. The reason for selecting the name was not given, nor is it explained in subsequent ICRU, ICRP, or for that matter, NCRP reports
There is a widespread belief that rad is an acronym for "radiation absorbed dose." This seems reasonable since many other contemporary units (the reb, rep and rem) were acronyms. However, if rad were an acronym, one would expect the ICRU to have identified it as such—something they did not do. If, on the other hand, the rad was just a convenient and concise name, there would be no reason for the ICRU to have explained it. The lack of any explanation in the official literature for the name is totally inconsistent with the idea that the rad is an acronym.
This issue is addressed explicitly by Dr. Lauriston Taylor, Chairman Emeritus of the ICRU (1990). In this article, Dr.Taylor states: "The term rad was simply suggested as a word by itself. Since then it has frequently been improperly referred to as an abbreviation for "radiation absorbed dose." This is simply incorrect."
Radiological (Radiation) Safety Officer
Radiological Safety Officer was the title given to the military officer who was responsible for radiological safety during the U.S. atomic weapons tests in the Pacific during the late 1940s.
The earliest use of this term that I know of was in Joint Task Force 7, the group established in 1947 to oversee Operation Sandstone at Enewetak. The regulations for Operation Sandstone read in part: "Permissible radiological exposure is established at 0.1 roentgens per twenty-four (24) hours. Under unusual circumstances, the Scientific Director and the Radiological Safety Officer may authorize a total exposure up to three (3) roentgens."
As Barton Hacker observed (1994), the regulation's careful wording was chosen to accommodate the sometimes conflicting needs of the military and scientific participants in the atomic tests. The military, represented by the Radiological Safety Officer, insisted on the ultimate authority for radiological safety, but the civilian scientists, represented by the Scientific Director, frequently needed to enter contaminated areas to perform their experiments and make radiation measurements. The physicist Karol Froman served as Joint Task Force 7's Scientific Director, and Col. James Cooney of the Army Medical Corps served as the Radiological Safety Officer. Cooney's position was essentially the same as that of Col. Stafford Warren in Joint Task Force 1 during Operation Crossroads at Bikini in 1946. Warren had been known as the Radiological Safety Advisor.
A distinction was sometimes attempted between the military's radiological measurements performed for the purpose of safety and the civilian radiation measurements performed for scientific purposes. Long after the atomic tests were completed in the Pacific, the military tended to favor the word "radiological" over "radiation."
Rem
A unit of the quantity dose equivalent, the rem replaced the reb, but the rem has now been superceded by the sievert.
Although the term was used as early as 1945, the rem made its first appearance in the scientific literature in 1950 in a paper by Herbert Parker. In this paper, Parker explained what the rem and another unit of his, the rep (predecessor of the rad), stood for: "The rep is an abbreviation of roentgen equivalent physical. The rem is an abbreviation of roentgen equivalent man or mammal. The more obvious choice of reb (roentgen equivalent biological) is avoided because of the confusion in speech between rep and reb."
Ron Kathren (1986) explains Parker's comment regarding a "confusion in speech" as follows: "The unit [the rem] was originally called the reb (roentgen equivalent biological), but during one of his early presentations of the new unit, Parker was suffering from a cold, which led to difficulty in differentiating it from the rep. Accordingly, the name of the unit was changed to rem."
Scram
Scram refers to the sudden shutdown of a reactor, usually by the insertion of control rods into the core. Also referred to as a trip.
The term appears to have been coined by Volney Wilson at the University of Chicago during WWII. Wilson was in charge of the instrumentation at Chicago Pile One (CP-1) when Enrico Fermi and his coworkers achieved the first controlled self-sustaining nuclear chain reaction. In particular, Wilson oversaw the construction of the pile's control rods.
Leona Marshall Libby, the only woman present at CP-1's initial criticality, had the following to say about the use of the term scram: "The safety rods were coated with cadmium foil, and this metal absorbed so many neutrons that the chain reaction was stopped. Volney Wilson called these ‘scram' rods. He said that the pile had ‘scrammed,' the rods had ‘scrammed' into the pile" (1979).
Scram is often said to be an acronym for "safety control rod axe man." A common variant, "safety control reactor axe man," is far less plausible because the word "reactor" was not in use at the time that the word scram was coined. The "axe man" being referred to is Norman Hilberry who stood by with an axe ready to cut a rope tied to the railing of the balcony overlooking the pile. At the other end of the rope was an emergency control rod. If the chain reaction got out of control, Hilberry was supposed to shut it down by cutting the rope and allowing the control rod to fall by gravity into the pile.
A problem with this explanation is that the word scram was applied to the process of shutting down the reactor or to the control rods; there is no record that scram was ever used to refer to Hilberry. Almost certainly, the "safety control rod axe man" story was developed as a humorous way to explain the origin of a newly invented word that lacked any other convenient explanation.
Carl Gamertsfelder, a health physicist who was present at the initial criticality, recalled that they joked that scram was what you did if there was a problem with the pile (personal communication with Ron Kathren).
X Rays
In the following sentence from his paper Ueber eine neue Art von Strahlung [On a New Kind of Ray] (28 December 1895), Röntgen used the term x rays for the first time in print:
"A piece of sheet aluminum, 15 mm thick, still allowed the X rays (as I will now call the rays, for the sake of brevity) to pass. . . . I find the justification for using the name ‘rays' for the agent emanating from the wall of the discharge apparatus in the very regular formation of shadows that are produced if one brings more or less transparent materials between the apparatus and the fluorescent screen (or the photographic plate)."
Brevity is the operative word in Röntgen's explanation for his choice of the term. Unlike some of his contemporaries (e.g., William Crookes), Röntgen was not one for flowery language. Designating the rays with a single letter was more his style.
Certainly Röntgen needed to select a name to distinguish these new rays from the other rays associated with gas discharge tubes (e.g., cathode rays and Lenard rays), but why did he choose the letter X? Why not call them Y rays or Z rays? The most common explanation is that Röntgen chose the term X rays to indicate that these rays were of an unknown nature. Although I know of nothing he wrote to suggest this, it makes sense—the letter x is used in mathematics to identify the principal unknown quantity.
