Particle Accelerators: Measuring Beam Profiles

Particle Accelerators: Measuring Beam Profiles

Particle accelerators caught the attention of the general public back in 2012 when particle physicists at CERN – the European Organization for Nuclear Research – discovered the Higgs boson; colloquially referred to as the God Particle. This breakthrough discovery resulted from decades of research and experimentation, alongside billions of dollars of investment into the now renowned large hadron collider (LHC).

The LHC is by far the world’s largest high energy particle accelerator, comprising a subterranean ring almost thirty kilometers in circumference and a multi-story complex filled with bespoke vacuum systems and complex particle detectors.

Today, physicists at CERN routinely study high-energy particle collisions providing insights into the fundamental laws of nature. Other particle accelerators, like that at the Australian Synchrotron facility, are used to generate extremely high intensity and energy electron beams to harness the resultant synchrotron radiation as a light source to probe material sample chemistry and structure in beamline experiments.

Although fundamentally different in terms of their purpose and size, all particle accelerators depend upon the precision engineering of ultra-high vacuum (UHV) devices including manipulators to measure the beam position, intensity, beam profile and divergence as the beam is linearly accelerated (2) and then circulates around the synchrotron.

How is Beam Profile Measured?

As the configuration of different circular particle accelerators, also referred to as synchrotrons, is entirely bespoke, there is no universal method of measuring beam intensity and position. In this portion of the article, we will focus on the LHC as it is the most familiar system worldwide.

CERN’s collider tunnel houses two parallel beamlines which accelerate particles, typically protons, to speeds approaching that of light. Radiofrequency (RF) cavities accelerate these particle beams while superconducting electromagnets alter the beam’s trajectory and focussing to keep it focussed and on this circular orbit, incrementally increasing in energy until such a point that the beams can be made intersect, and the particles collide.

Beam profile is a measure of the size and intensity cross section of particles present in the beam. The beam profile can be derived from measuring the resultant particle shower intensity v’s position when a fine wire is fast scanned across the beam.

UHV Design Products for Particle Accelerators

UHV Design is one of the world’s leading suppliers of vacuum-compatible manipulators for critical applications, such as accelerator beam diagnostics. We have worked closely with CERN and other pioneering particle physics facilities to develop specialized linear actuators and multi-axis sample manipulators that rise to the challenges of accelerator beam diagnostics.

If you would like more information about how we can assist with beam intensity and position monitoring in particle accelerators, simply contact a member of the UHV Design team today.