Beam position monitors are used in beam lines to gather information about the characteristics of the beam’s size, shape, location and time domain. As beam intensity increases in 3rd and 4th generation light sources, particularly with storage ring upgrades underway, diamond optical components are in demand more and more. The interaction of diamond with the x-ray beam enables a number of techniques to be used for beam position monitoring.
- Diamond Fluorescent Screens – Fluorescent screens can be used for intermittent checking of the beam. They’re dropped in place in order to check on beam quality and location and then removed to allow the beam to pass on to the experiment. The quality of the diamond used determines not only the color of the fluorescence but the resolution that can be achieved as grain boundaries, non-diamond carbon, and other defects act as electron traps reducing secondary emission. Diamond fluorescent screens are an appropriate choice for larger beams where visible detection of the fluorescence is possible.
- Diamond Blade Monitors – Photoemission – Diamond sheets, metalized with gold contacts, are arranged in a pattern within the beam path. As the x-ray beam interacts with the diamond, a current is generated in each blade proportional to the area of interaction. By observing the current intensity among the blades, the location of the beam determined. Diamond blade monitors are another appropriate choice for larger beams where reasonable gaps between blades can be set allowing for insignificant obstruction of the beam’s passage.
- Instrumented Diamond Windows – Photoconductive – For smaller beam sizes, thin diamond plates, with contacts applied, work well as monitors. The number of contacts can be varied from four (acting like the blade monitor example) to a pixelated version which supplies a digital image of the beam. Thicker diamond plates can double as a vacuum window for the beam line while thinner versions minimize absorption of lower energy photons and can be used anywhere in the beam line.
Applied Diamond supplies the variety of diamond materials needed to make these and other synchrotron beam line applications successful. We provide the engineering support you may need to simplify and speed the adoption of this remarkable material in your lab.