Введение
Пространственно локализованная группа электрически заряженных частиц, движущихся в одном направлении.
A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same position, kinetic energy (resulting in the same velocity), and direction. The kinetic energies of the particles are much larger than the energies of particles at ambient temperature. The high energy and directionality of charged particle beams make them useful for many applications in particle physics (see Particle beam#Applications and Electron beam technology). Such beams can be split into two main classes:
unbunched beams (coasting beams or DC beams), which have no longitudinal substructure in the direction of beam motion. bunched beams, in which the particles are distributed into pulses (bunches) of particles. Bunched beams are most common in modern facilities, since the most modern particle accelerators require bunched beams for acceleration. Assuming a normal distribution of particle positions and impulses, a charged particle beam (or a bunch of the beam) is characterized by
the species of particle, e. g. electrons, protons, or atomic nuclei
the mean energy of the particles, often expressed in electronvolts (typically keV to GeV)
the (average) particle current, often expressed in amperes
the particle beam size, often using the so called β function
the beam emittance, a measure of the area occupied by the beam in one of several phase spaces. These parameters can be expressed in various ways. For example, the current and beam size can be combined into the current density, and the current and energy (or beam voltage V) can be combined into the perveance K = I V−3/2. The charged particle beams that can be manipulated in particle accelerators can be subdivided into electron beams, ion beams and proton beams.
Луч заряженных частиц – это пространственно локализованная группа электрически заряженных частиц, имеющих приблизительно одинаковое положение, кинетическую энергию (что приводит к одинаковой скорости) и направление. Кинетические энергии частиц значительно превышают энергии частиц при комнатной температуре. Высокая энергия и направленность заряженных пучков частиц делают их полезными для множества применений в физике частиц (см. Пучок частиц#Приложения и технология электронных пучков). Такие пучки можно разделить на два основных класса: не сгруппированные пучки (пучки постоянного тока или непрерывные пучки), которые не имеют продольной структуры в направлении движения пучка, и сгруппированные пучки, в которых частицы распределены в импульсы (пачки) частиц. Сгруппированные пучки наиболее распространены в современных установках, поскольку самые современные ускорители частиц требуют сгруппированных пучков для ускорения. При нормальном распределении положений и импульсов частиц, заряженный пучок частиц (или пачка пучка) характеризуется:
A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same position, kinetic energy (resulting in the same velocity), and direction. The kinetic energies of the particles are much larger than the energies of particles at ambient temperature. The high energy and directionality of charged particle beams make them useful for many applications in particle physics (see Particle beam#Applications and Electron beam technology). Such beams can be split into two main classes:
unbunched beams (coasting beams or DC beams), which have no longitudinal substructure in the direction of beam motion. bunched beams, in which the particles are distributed into pulses (bunches) of particles. Bunched beams are most common in modern facilities, since the most modern particle accelerators require bunched beams for acceleration. Assuming a normal distribution of particle positions and impulses, a charged particle beam (or a bunch of the beam) is characterized by
the species of particle, e. g. electrons, protons, or atomic nuclei
the mean energy of the particles, often expressed in electronvolts (typically keV to GeV)
the (average) particle current, often expressed in amperes
the particle beam size, often using the so called β function
the beam emittance, a measure of the area occupied by the beam in one of several phase spaces. These parameters can be expressed in various ways. For example, the current and beam size can be combined into the current density, and the current and energy (or beam voltage V) can be combined into the perveance K = I V−3/2. The charged particle beams that can be manipulated in particle accelerators can be subdivided into electron beams, ion beams and proton beams.
видом частиц, например, электронами, протонами или атомными ядрами;
средней энергией частиц, часто выражаемой в электронвольтах (обычно от кэВ до ГэВ);
(средним) током частиц, часто выражаемым в амперах;
размером пучка частиц, часто определяемым так называемой бета-функцией (β-функцией);
эмиттансом пучка – мерой площади, занимаемой пучком в одном из фазовых пространств.
A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same position, kinetic energy (resulting in the same velocity), and direction. The kinetic energies of the particles are much larger than the energies of particles at ambient temperature. The high energy and directionality of charged particle beams make them useful for many applications in particle physics (see Particle beam#Applications and Electron beam technology). Such beams can be split into two main classes:
unbunched beams (coasting beams or DC beams), which have no longitudinal substructure in the direction of beam motion. bunched beams, in which the particles are distributed into pulses (bunches) of particles. Bunched beams are most common in modern facilities, since the most modern particle accelerators require bunched beams for acceleration. Assuming a normal distribution of particle positions and impulses, a charged particle beam (or a bunch of the beam) is characterized by
the species of particle, e. g. electrons, protons, or atomic nuclei
the mean energy of the particles, often expressed in electronvolts (typically keV to GeV)
the (average) particle current, often expressed in amperes
the particle beam size, often using the so called β function
the beam emittance, a measure of the area occupied by the beam in one of several phase spaces. These parameters can be expressed in various ways. For example, the current and beam size can be combined into the current density, and the current and energy (or beam voltage V) can be combined into the perveance K = I V−3/2. The charged particle beams that can be manipulated in particle accelerators can be subdivided into electron beams, ion beams and proton beams.
Эти параметры могут быть выражены различными способами. Например, ток и размер пучка можно объединить в плотность тока, а ток и энергию (или напряжение пучка V) – в первеанс K = I V−3/2. Заряженные пучки частиц, которыми можно управлять в ускорителях частиц, подразделяются на электронные пучки, ионные пучки и протонные пучки.
A charged particle beam is a spatially localized group of electrically charged particles that have approximately the same position, kinetic energy (resulting in the same velocity), and direction. The kinetic energies of the particles are much larger than the energies of particles at ambient temperature. The high energy and directionality of charged particle beams make them useful for many applications in particle physics (see Particle beam#Applications and Electron beam technology). Such beams can be split into two main classes:
unbunched beams (coasting beams or DC beams), which have no longitudinal substructure in the direction of beam motion. bunched beams, in which the particles are distributed into pulses (bunches) of particles. Bunched beams are most common in modern facilities, since the most modern particle accelerators require bunched beams for acceleration. Assuming a normal distribution of particle positions and impulses, a charged particle beam (or a bunch of the beam) is characterized by
the species of particle, e. g. electrons, protons, or atomic nuclei
the mean energy of the particles, often expressed in electronvolts (typically keV to GeV)
the (average) particle current, often expressed in amperes
the particle beam size, often using the so called β function
the beam emittance, a measure of the area occupied by the beam in one of several phase spaces. These parameters can be expressed in various ways. For example, the current and beam size can be combined into the current density, and the current and energy (or beam voltage V) can be combined into the perveance K = I V−3/2. The charged particle beams that can be manipulated in particle accelerators can be subdivided into electron beams, ion beams and proton beams.
Общие типы
Электронный луч, или катодный луч, как, например, в сканирующем электронном микроскопе или в ускорителях, таких как Большой электронно-позитронный коллайдер или источники синхротронного излучения. Протонный луч, например, используемый в протонной терапии, на коллайдерах, таких как Теватрон и Большой адронный коллайдер, или для протонно-лучевой записи в литографии. Ионные лучи, как, например, в релятивистском коллайдере тяжелых ионов или на Установке для получения редких изотопных пучков.