Stroboscopic Laser Diagnostics for Detection of Ordering in OneDimensional Ion beam.pdf

Stroboscopic Laser Diagnostics for Detection of Ordering in One-Dimensional Ion beam. R. Calabrese†, V. Guidi†, P.Lenisa†, E. Mariotti§, L. Moi§ and U.Tambini† 5 9 9 †Dipartimento di Fisica dell’Universit`a, I-44100 Ferrara, Italy; INFN - Sezione di Ferrara, Italy. 1 y §Dipartimento di Fisica dell’Universit`a, I-53100 Siena, Italy. a M (February 5, 2008) 5 2 2 v Abstract 2 0 0 5 A novel diagnostic method for detecting ordering in one-dimensional ion 0 5 beams is presented. The ions are excited by a pulsed laser at two different 9 / s positions along the beam and fluorescence is observed by a group of four y h photomultipliers. Correlation in fluorescence signals is firm indication that p - c the ion beam has an ordered structure. c a 32.80.-t, 41.75.-i, 29.20 : v i X r a Typeset using REVT X E 1 I. INTRODUCTION In the past few years the interest in the field of ion crystallization has become increasingly stronger from both theoretical and experimental points of view. This research effort has led to the successful detection of crystallization in an ion trap [1] and in a mini-quadrupole storage ring [2]. In these systems, ions are at rest in the laboratory frame and the transition to the ordered state is achieved by laser cooling [3]. At the same time, the possibility has been suggested to cool an ion beam in a storage ring to the extent that a crystalline ph