inhour

inhour
(ih or inhr)
   a unit used in nuclear engineering to describe the "reactivity" of a nuclear reactor. In a reactor, fast-moving neutrons break apart atoms of uranium or plutonium; the fission of these atoms releases additional neutrons which keep the reaction going. The ratio R between the number of neutrons created and the number consumed in each cycle of fission must be very close to 1 in order for the reaction to be controlled. The reactivity is the difference k = R - 1 between this ratio and 1. One inhour is the reactivity which will cause the number of neutrons to increase by a factor of e = 2.71828 in one hour; a reactivity of t inhours will cause the number of neutrons to increase by a factor of e in 1/t hours. The exact size of the unit varies according to the design of the reactor. Enrico Fermi (1901-1954), the Italian-American physicist who built the first nuclear reactor, introduced this unit in 1947; its name is an acronym for "inverse hours." Other reactivity measures include the dollar and the milli-k.

Dictionary of units of measurement. 2015.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • InHour — is a unit of activity of a nuclear reactor. It stands for the inverse of an hour. It is equal to the inverse of the period in hours. One InHour is the amount of reactivity needed to increase the reaction by a factor of e in one hour. [cite book… …   Wikipedia

  • inhour — …   Useful english dictionary

  • Nectanebo II — Nectanébo II Articles de la série Pharaon Classements alphabétique chronologique Dynasties 0  …   Wikipédia en Français

  • Nectanébo II — Articles de la série Pharaon Classements alphabétique chronologique Dynasties 0  …   Wikipédia en Français

  • Teos (pharaon) — Téos (pharaon) Pour les articles homonymes, voir Téos. Articles de la série Pharaon Classements alphabétique …   Wikipédia en Français

  • Téos (pharaon) — Pour les articles homonymes, voir Téos. Articles de la série Pharaon Classements …   Wikipédia en Français

  • обратный час — (единица реактивности) [А.С.Гольдберг. Англо русский энергетический словарь. 2006 г.] Тематики энергетика в целом EN inhour …   Справочник технического переводчика

  • cent —    1. an old English unit of quantity, usually equal to 100 but sometimes 120 (the great or long hundred) or some other figure of similar size. The Latin number 100, centum, is also used in English works for this quantity.    2. an informal name… …   Dictionary of units of measurement

  • dollar — ($)    a unit used in nuclear engineering to describe the reactivity of a nuclear reactor. For a particular reactor, one dollar is the reactivity at which the chain reaction is just self sustaining. The size of the unit varies with the design of… …   Dictionary of units of measurement

  • ih —    see inhour …   Dictionary of units of measurement

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”