Astronomers regularly study naturally occurring synchrotron radiation from space and calibrate telescopes to detect this radiation. These same techniques can be applied to synchrotron radiation generated by particle accelerators – used in a wide range of medical and other scientific research here on Earth – to ensure they are working at their best quality possible.

Huge magnetic fields in space energise and accelerate charged subatomic particles to relativistic speeds producing extremely energetic radiation (synchrotron). Studying the resulting beams of radiation helps us understand the composition and forces of the Universe. These beams are so faint, however, that telescopes on Earth need to be precisely fine-tuned and calibrated. An incorrect calibration results in unusable science products.

While calibrating these atomic signals using interferometry is well known to radio astronomers, this technique is not widely used in other contexts.

Astronomers at CSIRO, Australia’s national science agency, partnered with USA’s NRAO, the University of Cambridge and a team at Spain’s synchrotron-generating particle accelerator, ALBA, to develop and implement new calibration systems that could determine the quality of the accelerator’s electron beams. Existing calibration techniques had remained largely the same for over 30 years and had limitations – requiring multiple steps, cumbersome processes that did not allow real-time estimates of the beam quality, and large amounts of time and data. Applying techniques from radio astronomy offered a way to more succinctly and accurately calibrate the synchrotron beam more quickly and using less data.

Through innovative collaboration and by introducing powerful radio interferometry concepts, developed through experience in synthesis imaging in radio astronomy, researchers could precisely characterise the accelerator’s beams in ways that couldn’t be done with existing methods. Application of this technique will enable fine-tuning the particle accelerator’s control systems to transport and deliver the highest quality particle beams possible to serve various scientific, medical, and technological purposes.

CSIRO Science Lead Dr Nithyanandan Thyagarajan said this project was the first for this cross-disciplinary and international partnership.

“This represents one of the first real-world applications of powerful interferometric concepts like self-calibration and closure invariants developed for astronomy to wavefront sensing and to directly determine a light source’s shape profile and thereby enable better focussing for higher quality. Using techniques from radio astronomy interferometry led to efficient, reliable and accurate measurements in real time at a practical speed, lower data rates, and reduced computational overhead.

“Translation of these astronomy techniques and skills to other scientific and technological disciplines, and instrumentation is now being investigated,” he said.

Read the related papers:

• Physical Review Accelerators and Beams: Two-dimensional synchrotron beam characterization from a single interferogram, which outlines the introduction of radio astronomy techniques to particle accelerator diagnostics
• Journal of the Optical Society of America A: Two-dimensional light beam shape characterization using interferometric closure amplitudes, which is was an even more novel alternative to the above paper’s approach.