Upgrade of the Infrared Camera Diagnostics for the JET ITER-Like Wall Divertor
For the new ITER-Like Wall (ILW) at JET, two new infrared diagnostics (KL9B, KL3B) have been installed. These diagnostics can operate between 3.5-5µm and up to sampling frequencies of ~20kHz. KL9B and KL3B image the horizontal and vertical tiles of the divertor. The divertor tiles are tungsten coated Carbon Fibre Composite (CFC) except the central tile which is bulk tungsten and consists of lamella segments. The thermal emission between lamellae affects the surface temperature measurement and therefore KL9A has been upgraded to achieve a higher spatial resolution (by a factor of 2). A technical description of KL9A, KL9B and KL3B and cross correlation with a Near InfraRed (NIR) camera and a 2-color pyrometer is presented.