| cyclotron | <radiobiology> Particle accelerator in which a magnetic field causes particles to orbit in circles, and an oscillating electric field accelerates the particles. (09 Oct 1997) |
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| cyclotron frequency | <radiobiology> Number of times per second that a particle orbits a magnetic field line. The frequency is completely determined by the strength of the field and the particle's charge-to-mass ratio. (Often, and incorrectly, called the Larmor frequency. The cyclotron or gyrofrequency is twice the Larmor frequency of precession.) (09 Oct 1997) |
| cyclotron radius | <radiobiology> Radius of orbit of charged particle about a magnetic field line. Synonym: gyroradius, Larmor radius. (09 Oct 1997) |
| cyclotron resonance | <radiobiology> Charged particles in a magnetic field resonate with (and absorb energy from) an electric field (perpendicular to the magnetic field) which oscillates at the particles' cyclotron frequency, or at a harmonic (multiple) of that frequency. (09 Oct 1997) |
| cyclotrons | Devices for accelerating charged particles in a spiral path by a constant-frequency alternating electric field. This electric field is synchronised with the movement of the particles in a constant magnetic field. (12 Dec 1998) |
| Alfven ion cyclotron instability | <radiobiology> An electromagnetic microinstability near the ion cyclotron frequency, driven by the ion loss cone in a mirror device. Acronym: AIC (13 Nov 1997) |
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| drift cyclotron loss cone instabilities | (DCLC) This is an electrostatic microinstability (frequencies at harmonics of the ion cyclotron frequency) which is of major concern in small mirror devices. Mode is driven by radial gradients in the electron density, and causes loss of ions due to non-conservation of magnetic moment (see adiabatic invariant) as they interact with the mode, and are dispersed in velocity space into the loss cone. Stabilisation is accomplished by increasing the plasma size and by partially filling the loss cone with a continuous extermal warm plasma stream. (09 Oct 1997) |
| ion cyclotron emission | <radiobiology> As ions gyrate around in a magnetic field (see also larmor radius or cyclotron radius), they radiate radio-frequency electromagnetic waves. This is known as ion cyclotron emission, and can be measured to help diagnose a plasma. (09 Oct 1997) |
| electron cyclotron discharge cleaning | Using relatively low power microwaves (at the electron cyclotron frequency) to create a weakly ionised, essentially unconfined hydrogen plasma in the vacuum chamber. The ions react with impurities on the walls of the tokamak and help remove them from the chamber. For instance, Alcator C-mod typically applies electron cyclotron discharge cleaning for a few days prior to beginning a campaign, and a few hours before each day's run. (09 Oct 1997) |
| electron cyclotron emission | <physics, radiobiology> As electrons gyrate around in a magnetic field (see also larmor radius or cyclotron radius), they radiate radio-frequency electromagnetic waves. This is known as electron cyclotron emission, and can be measured to help diagnose a plasma. (09 Oct 1997) |
| electron cyclotron heating | <physics, radiobiology> Radiofrequency heating scheme that works by injecting electromagnetic wave energy at the electron cyclotron gyration frequency. The electric field of the electromagnetic wave at this frequency looks to a gyrating electron like a static electric field, and thus causes large acceleration of the electron (larger than if the frequency were off the cyclotron frequency and thus, to the electron, appearing to change direction as a function of time). The accelerated electron gains energy, which is then shared with other particles through collisions, resulting in heating. Higher harmonics (multiples) of the cyclotron frequency can also be used in principle. (09 Oct 1997) |