The reactor won’t restart until April 2022 at the earliest, leaving thousands of users scrambling to find beamtime elsewhere.
beamtime (usually uncountable, plural beamtimes) (physics) time allocated to a researcher for use of a beam of particles from a particular source.
Etymology[edit]
Noun[edit]
beam (plural beams)
- Any large piece of timber or iron long in proportion to its thickness, and prepared for use. quotations ▼
- One of the principal horizontal structural members, usually of timber or concrete, of a building; one of the transverse members of a ship's frame on which the decks are laid — supported at the sides by knees in wooden ships and by stringers in steel ones. quotations ▼
- (nautical) The maximum width of a vessel (note that a vessel with a beam of 15 foot can also be said to be 15 foot abeam). quotations ▼
- Synonym: breadth
- This ship has more beam than that one.
- The crossbar of a mechanical balance, from the ends of which the scales are suspended. quotations ▼
- The principal stem of the antler of a deer.
- (literary) The pole of a carriage or chariot. quotations ▼
- (textiles) A cylinder of wood, making part of a loom, on which weavers wind the warp before weaving and the cylinder on which the cloth is rolled, as it is woven.
- The straight part or shank of an anchor.
- The central bar of a plow, to which the handles and colter are secured, and to the end of which are attached the oxen or horses that draw it.
- In steam engines, a heavy iron lever having an oscillating motion on a central axis, one end of which is connected with the piston rod from which it receives motion, and the other with the crank of the wheel shaft.
- Synonyms: working beam, walking beam
- A ray or collection of approximately parallel rays emitted from the sun or other luminous body. quotations ▼
- a beam of light
- a beam of energy
- (figuratively) A ray; a gleam. quotations ▼
- a beam of hope, or of comfort
- One of the long feathers in the wing of a hawk.
- Synonym: beam feather
- (music) A horizontal bar which connects the stems of two or more notes to group them and to indicate metric value.
- (railway) An elevated rectangular dirt pile used to cheaply build an elevated portion of a railway.
- (gymnastics) Ellipsis of balance beam
OED
7.
a. In Physics I (rarely i) is the symbol of the quantum number of nuclear spin. [Adopted by Back and Goudsmit 1928, in Zeitschr. f. Physik XLVII. 175.]
1930 L. Pauling & S. Goudsmit Struct. Line Spectra xi. 203 i is a new quantum number, the nuclear spin quantum number.
1932 R. F. Bacher & S. Goudsmit Atomic Energy States 20 The spectrum of bismuth, for which the nuclear moment I is 4½, is an interesting example of this type of hyperfine structure.
1966 D. H. Whiffen Spectrosc. iii. 22 Intrinsic nuclear angular momenta are quantised and may be expressed as Iħ where I..is called the spin quantum number.
1967 E. U. Condon & H. Odishaw Handbk. Physics (ed. 2) vii. iv. 68/1 At low magnetic fields I and J are tightly coupled to form a resultant angular momentum F = I + J, whose quantum number F at low fields is a good quantum number.
b. Occasionally used as the symbol of the quantum number of isospin (more commonly T n.).
1953 Progress Theoret. Physics 9 420 In general, selection rules are intimately connected with the conservative quantities which we shall inquire for a system involving Fermions. Those are the total angular momentum J and the total isotopic spin I of the system.
1962 A. Ramakrishnan Elem. Particles & Cosmic Rays i. 31 We use the symbol t for the isotopic spin operator of a system of particles and τ for a single particle, their eigenvalues being denoted by T and I respectively.
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