The Importance of Proper Beamline Technique
The scientific community is excited about the faster and brighter beamlines that are increasingly available for their innovative work. However, when constraints are mitigated by technology advancement — in this case speed constraints — better technique is often needed to maximize opportunities for both discovery and leadership. Offering orders of magnitude more photon flux, tomorrow’s brighter beamlines will make groundbreaking research possible in the areas of materials science, life sciences and soft matter, environmental sciences and cultural heritage. Proper technique development and use will be essential for researchers that want to succeed in the coming years.
One area in which technique development will be critical is in synchrotrons that access a pink beam but where images rates don’t reach the MHz regime. Where improved brightness or flux levels may mean KHz imaging becomes a reality the direct beam will not be photon-starved. A standard approach in the past has been to use attenuators or beam stops to shield the detector from the direct beam. Given the technology available, this was the only way to make it possible to do single photon counting of the specimen signal. The drawback of this is that information about the direct beam at the time of signal acquisition is lost.
Choosing the Right Beamline Technique
Today, there are detectors that combine single photon sensitivity with an ultra wide dynamic range. For instance, the Sydor MM-PAD detector can capture single photons while enabling a sustained count rate of half a billion photons per pixel per second. This capability can eliminate the need for an attenuator on the direct beam, and potentially enable scientists to develop techniques that utilize the direct beam information in the processing of their data.
In all areas of research, it is important to choose the right technique, considering the nature of the sample being tested and the information sought. These techniques depend on and can benefit from new detector capabilities. Broadly, if time resolved experiments are needed, then use a high frame rate detector, one that is designed for direct detection of x-rays. On the other hand, if single-photon counting is needed, then select a detector that has a wide enough dynamic range to eliminate the need for an attenuator on the direct beam. In either case, consider how to extend existing techniques to take advantage of detector performance. The payoff could be innovative experiments that lead to significant findings and thought leadership opportunities.