Particle Accelerator Physics

Transverse-emittance measurements on an S-band photocathode RF electron gun

“…The beam widths are averaged over the five data points and the emittance fit uses weighting inversely proportional to the rms spread in the data points. The emittance fit is calculated using the standard linear matrix along the beam line [7] and thus does not include space charge along the drift region between quadrupole and screen. A typical quadrupole scan is shown in Figure 2 with the measured rms beam sizes as a function of the quadrupole strength plotted as diamonds.…”

Diffraction and depths-of-field effects in electron beam imaging at SURF III

“…At low electron energies, the electron beam lifetime is dominated by Touschek scattering [9]. The Touschek lifetime is proportional to the electron bunch volume.…”

“…The vertical angular distribution of magnetobremsstrahlung or synchrotron radiation is important for the experimental and theoretical analysis, because it plays a central role both for depth-of-field and diffraction effects in beam size measurements. Wiedemann [9,10] gives a good review on the origins and properties of synchrotron radiation in his books on accelerator physics. To a good approximation the vertical opening half-angle c typ depends only on the bending radius and the wavelength c typ ¼ 3 ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 3l=4pr 0 p , if l4l c (the critical wavelength).…”

Stimulated coherent transition radiation

“…where e is the electronic charge, m is the electronic mass, y is the Lorentz factor, and the units of the quantities are listed in the associated square brackets [6]. In the results, the calculated power is normalized to that emitted from a single electron bunch in each pass and is converted to spectral photon flux (in photons/sec/lOO% on-axis observation of the cylindrically symmetric electron beam is assumed in these calculations.…”