Fusion research at Culham
Self sustaining thermonuclear burn in a plasma, with an equal mix of deuterium and tritium isotopes, requires the product of particle density and energy confinement time to exceed 1020m-3s. Ion temperatures in excess of 10keV (~108 Kelvin) are also required. The UKAEA Culham Laboratory has played a key role in this research since the 1960s. It now has two plasma machines: one mainly for Magnetohydrodynamics (MHD) and confinement research ("COMPASS-D") and the other is a novel device with an almost spherical-shaped plasma ("MAST"). The site is also host to the JET experiment which leads the world and is closest to ignition conditions. Highlights from this work will be discussed.
Dr Patrick Carolan has been engaged in fusion related physics since the late 1960s. He has been involved in many plasma physics areas and has pioneered diagnostic techniques involving laser systems and high resolution spectrometers. Following his M Sc in opto-electronics, from Queens University Belfast, he went to the UKAEA Culham Laboratory to do his Ph D (QUB), being the first to measure plasma magnetic fields by Thomson scattering, using a Q-switched ruby laser. He then spent four years at the KFA (Kernforschunsanlage) centre at Juelich, Germany, researching a shock-heated toroidal plasma device ("Tokamak" configuration). On returning to Culham (1976) he led the physics effort in designing a new plasma device whose magnetic fields were largely self generated ("Reversed Field Pinch") by dynamo action similar to that generating the Earth’s magnetic field. This led to a sequence of machines, terminating in 1991, producing some very interesting physics, including ion heating from plasma relaxation involved in the field generation. Throughout this period he maintained an active interest in Tokamak physics, including JET, and is now the Particle Dynamics group leader for the COMPASS-D and MAST Tokamaks. His present interests include the edge physics governing the enhanced plasma performance. These include the effects of rapid plasma spinning to suppress turbulence. He was a visiting scientist to various laboratories including the Electrotechnical Laboratory at Tsukuba (Japan), Max Planck IPP Garching (Germany), Los Alamos (USA) and the Rutherford Appleton Laboratory (UK). He has kept close contact with Irish universities and has Ph D students from UCC, UCD and QUB.