Results from a prototype beam monitor in the Tevatron using synchrotron light
A prototype synchrotron light monitor has been installed in the Tevatron at the downstream edge of a superconducting dipole magnet. Synchrotron light produced at the upstream edge of the magnet is sufficiently separated from the proton beam to be picked off by the monitor's mirror and diverted to its detector. It is shown that the way to enrich the low-wavelength region is to rely either upon short magnets (or an undulator which is a series of short magnets) or the sharp transition between the zero field region and the full-field region of a dipole magnet. The measured light intensity at different beam energies was compared to the predicted values. The parameters of a beam profile monitor are discussed.<<ETX>>
Radiation from moving charged particles with spin
The theory of radiation emitted by a charged particle with spin in relativistic motion in an external magnetic field is reviewed. Approximate expressions suitable numerical computation, in far and near field, are derived. In particular, the case of the passage of a particle accelerator beam through an undulator is considered. It is shown that observation of the spectrum of the emitted radiation, in its two states of polarization, can be used not only for beam diagnostics, but also to measure the spin state of the accelerated particles. Undulator radiation is compared with Compton scattering of laser light by the particle beam. Examples for high energy electron and proton colliders are presented.
Magnetic plasma confinement for laser ion source.
A laser ion source (LIS) can easily provide a high current beam. However, it has been difficult to obtain a longer beam pulse while keeping a high current. On occasion, longer beam pulses are required by certain applications. For example, more than 10 micros of beam pulse is required for injecting highly charged beams to a large sized synchrotron. To extend beam pulse width, a solenoid field was applied at the drift space of the LIS at Brookhaven National Laboratory. The solenoid field suppressed the diverging angle of the expanding plasma and the beam pulse was widened. Also, it was observed that the plasma state was conserved after passing through a few hundred gauss of the 480 mm length solenoid field.