Enhancements to the JET poloidally scanning vacuum ultravioletvisible spectrometers
2012 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 83, no 10, 10D536- p.Article in journal (Refereed) Published
Enhancements to the JET poloidally scanning spectrometers are presented, which will aid the exploitation of the recently installed ITER-like wall in JET. They include the installation of visible filterphotomultiplier tube assemblies and spectrometers and the replacement of large rotating mirrors in the JET vacuum with small oscillating mirrors outside. The upgrade has resulted in a more robust and reliable diagnostic than before, which is described. Drifts in the mirror angle reconstructed from quadrature encoder signals are found, a reference signal being required. The use of the small scanning mirrors necessitated the inclusion of focusing mirrors to maintain throughput into the vacuum ultraviolet spectrometers. The mirror design has taken account of the extreme sensitivity of the focusing to the grazing angle of incidence, an aspect of importance in the design of grazing incidence focusing components on future machines, such as ITER. The visible system has been absolutely calibrated using an in-vessel light source.
Place, publisher, year, edition, pages
2012. Vol. 83, no 10, 10D536- p.
Focusing, Light sources, Mirrors, Scanning, Spectrometry, Vacuum
IdentifiersURN: urn:nbn:se:kth:diva-106960DOI: 10.1063/1.4745213ISI: 000311562900055ScopusID: 2-s2.0-84868367155OAI: oai:DiVA.org:kth-106960DiVA: diva2:574259
QC 201212052012-12-052012-12-052013-01-08Bibliographically approved