A novel longitudinal laserwire to non-invasively measure 6-dimensional bunch parameters at high current hydrogen ion accelerators. / Gibson, Stephen; Alden, Siobhan; Bosco, Alessio; Letchford, Alan; Pozimski, Juergen.

In: Journal of Physics: Conference Series, Vol. 1067, 072016, 05.10.2018, p. 1-7.

Research output: Contribution to journalArticle

E-pub ahead of print


Optical methods for non-invasive beam diagnostics of high current H− ion accelerators have been developed in recent years. Such laserwires typically measure a 1D beam profile and/or 2D transverse emittance from the products of photo-detached ions as a laser beam is scanned across the H− beam. For laser pulse durations (~80 ns) longer than the RF period (~3ns), the detector integrates many complete bunches, enabling only transverse beam monitoring. This paper presents a new technique to capture a series of time resolved transverse emittance measurements along the bunch train. A fast (~10 ps) pulsed laser photo-detaches ions within each bunch and is synchronised to sample consecutive bunches at certain longitudinal positions along each bunch. A fast detector records the spatial distribution and time-of-flight of the neutralised H0, thus both the transverse and longitudinal emittance are reconstructed. We present simulations of a time varying pulsed laser field interacting within an H− bunch, and estimate the yield, spatial and time distributions of H0 arriving at the detector. We summarise the design of a recently funded longitudinal laserwire being installed in FETS at RAL, UK.
Original languageEnglish
Article number072016
Pages (from-to)1-7
Number of pages7
JournalJournal of Physics: Conference Series
Early online date5 Oct 2018
Publication statusE-pub ahead of print - 5 Oct 2018
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

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