title: X-ray crystal spectrometer upgrade for ITER-like wall experiments at JET.
abstract: The high resolution X-Ray crystal spectrometer at the JET tokamak has been upgraded with the main goal of measuring the tungsten impurity concentration. This is important for understanding impurity accumulation in the plasma after installation of the JET ITER-like wall (main chamber: Be, divertor: W). This contribution provides details of the upgraded spectrometer with a focus on the aspects important for spectral analysis and plasma parameter calculation. In particular, we describe the determination of the spectrometer sensitivity: important for impurity concentration determination.
authors.affiliation: JET-EFDA, Culham Science Centre, Abingdon OX14 3DB, United Kingdom.
authors.forename: A E
authors.initials: AE
authors.lastname: Shumack
authors.affiliation: National Centre for Nuclear Research, Andrzeja Sołtana 7, 05-400 Otwock, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Rzadkiewicz
authors.affiliation: Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Chernyshova
authors.affiliation: Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Jakubowska
authors.affiliation: Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Scholz
authors.affiliation: Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warsaw, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Byszuk
authors.affiliation: Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warsaw, Poland.
authors.forename: R
authors.initials: R
authors.lastname: Cieszewski
authors.affiliation: Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland.
authors.forename: T
authors.initials: T
authors.lastname: Czarski
authors.affiliation: Faculty of Physics, Institute of Experimental Physics, Warsaw University, 00-681 Warsaw, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Dominik
authors.affiliation: Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw, Poland.
authors.forename: L
authors.initials: L
authors.lastname: Karpinski
authors.affiliation: Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warsaw, Poland.
authors.forename: G
authors.initials: G
authors.lastname: Kasprowicz
authors.affiliation: Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warsaw, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Pozniak
authors.affiliation: Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warsaw, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Wojenski
authors.affiliation: Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warsaw, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Zabolotny
authors.affiliation: JET-EFDA, Culham Science Centre, Abingdon OX14 3DB, United Kingdom.
authors.forename: N J
authors.initials: NJ
authors.lastname: Conway
authors.affiliation: JET-EFDA, Culham Science Centre, Abingdon OX14 3DB, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Dalley
authors.affiliation: EFDA-CSU, Culham Science Centre, Abingdon OX14 3DB, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Figueiredo
authors.affiliation: Japan Atomic Energy Agency, Naka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakano
authors.affiliation: JET-EFDA, Culham Science Centre, Abingdon OX14 3DB, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Tyrrell
authors.affiliation: JET-EFDA, Culham Science Centre, Abingdon OX14 3DB, United Kingdom.
authors.forename: K-D
authors.initials: KD
authors.lastname: Zastrow
authors.affiliation: The National Institute for Laser, Plasma and Radiation Physics, Association EURATOM-MEdC, Magurele-Bucharest, Romania.
authors.forename: V
authors.initials: V
authors.lastname: Zoita