For instance, if a graduate student has the scintillating screen in a dispersive beamline, a pair of sextupoles, and a lot of free time in his posession, he might be able to obtain a beam image like that.
For instance, if a graduate student has the scintillating screen in a dispersive beamline, a pair of sextupoles, and a lot of free time in his posession, he might be able to obtain a beam image like that.
In most of the accelerator facilities the transverse size of the electron beam is determined through direct visualization of the electron beam with the beam profile monitors. The beam path is intersected by the scintillating screen, which generates an electron beam image upon the impact. The screen is visualized with the CCD camera, so the image can be recorded and analysed. Such technique, however, has significant limitations: while scintillators are ideal tools for the visualization of the millimiter spot-sizes, their resolution become somewhat limited, once the intense electron beams are focused down to the sub-100 µm spots.
For such small beams, it is better to use the OTR imaging (Optical Transition Radiation), which is a single-shot technique, conceptually simple and easy to implement. OTR imaging resolution is restricted by the collecting optics resolution, so for the very small bunches (sub-10 µm), one is forced to use more exotic techniques, such as wire scanners.
Another problem occurs with the beams of high energy and large average current. Then, the heat deposited by the beam can become significant to destroy the interceptive diagnostics, and sophisticated non-destructive techniques have to be employed.