In search of huts. I have been on a mission to locate and document the remaining huts from a cosmic ray detection experiment at Haverah Park on the Pennine moorland in North Yorkshire. When high-energy cosmic rays enter the atmosphere, they set off a chain-reaction particle cascade known as an extensive air shower. The Haverah Park experiment was home to one of the largest extensive cosmic ray air shower arrays in the world.
It was operated by the Physics Department of the University of Leeds for 20 years, closing in The large energy density of cosmic rays is close to that of starlight, adding their own glow to the sky as they blast across the universe. Cosmic rays are the atomic nuclei of elements ranging from hydrogen to uranium accelerated to high energies, with half being protons and most positively charged.
Much of the technology used to observe cosmic rays has changed little over the decades since first inventions and still plays a role within newer technologies. It appeals to me that the excitement of observing particles from other galaxies happened at these unassuming structures. Sharing the landscape of Haverah Park cosmic ray air shower detector array huts are the striking white radomes that shield secret radar equipment at RAF Menwith Hill.
The spy station has been there since the cold war space race began in the mid-fifties. As satellite technology has increased so has the number of radomes which now number 37 at the site. It is worth noting that satellites are vulnerable to unpredictable space weather and cosmic ray interference. The total number of particles detected in a shower can be used to estimate the energy of the primary cosmic ray. The difference in the time of arrival of recorded particles at multiple detectors can be used to estimate the arrival direction of the primary cosmic ray.
However, this does not necessarily reveal the origin of the particle as magnetic fields within the galaxies bend their trajectories so that the memory of their original direction is obfuscated. The cosmic ray detectors I made for the The Breath of Stars use a block of plastic scintillator which emits a short burst of UV light when a charged particle passes through it which is picked up by a single-photon-sensitive device.
