title: Upgrade of the infrared camera diagnostics for the JET ITER-like wall             divertor.
abstract: For the new ITER-like wall at JET, two new infrared diagnostics (KL9B, KL3B) have             been installed. These diagnostics can operate between 3.5 and 5 μm and up to             sampling frequencies of ∼20 kHz. KL9B and KL3B image the horizontal and vertical             tiles of the divertor. The divertor tiles are tungsten coated carbon fiber composite             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 camera and a two-color pyrometer is presented.
authors.affiliation: EURATOM∕CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB, United Kingdom. itziar.balboa@ccfe.ac.uk
authors.forename: I
authors.initials: I
authors.lastname: Balboa
authors.forename: G
authors.initials: G
authors.lastname: Arnoux
authors.forename: T
authors.initials: T
authors.lastname: Eich
authors.forename: B
authors.initials: B
authors.lastname: Sieglin
authors.forename: S
authors.initials: S
authors.lastname: Devaux
authors.forename: W
authors.initials: W
authors.lastname: Zeidner
authors.forename: C
authors.initials: C
authors.lastname: Morlock
authors.forename: U
authors.initials: U
authors.lastname: Kruezi
authors.forename: G
authors.initials: G
authors.lastname: Sergienko
authors.forename: D
authors.initials: D
authors.lastname: Kinna
authors.forename: P D
authors.initials: PD
authors.lastname: Thomas
authors.forename: M
authors.initials: M
authors.lastname: Rack