No. 29 (2002): Neutrino Factories
Editors-in-Chief: W. Chou and J.M. Jowett, Editors: C. Biscari, S. Chattopadhyay, S. Ivanov, A.M. Lombardi, H. Mais, J. Wei, and C. Zhang
This issue of the ICFA Beam Dynamics Newsletter has been edited by a new member of the editorial team, Dr Alessandra Lombardi, who joined the Beam Dynamics Panel earlier this year. She has chosen the special theme of Neutrino Factories, one of the brightest hopes for extending the reach of particle accelerators into regions of unexplored physics beyond those that will be opened up by the LHC and, we hope, a linear collider.
The general scheme of a neutrino factory is the following: a high power proton beam (of few MW) is sent on a (mercury) target; the forward going pions are collected and decay into muons. The pions/muons energy distribution is peaked around 200 MeV almost independently of the primary beam energy. Muons are further manipulated (phase rotation and ionization cooling) before being accelerated to energies of several tens of GeV and stored in a ring where they decay into neutrinos. The possibility of selecting at the source positive or negative muons allows for a beam containing only one flavour neutrino at the time; a condition which is necessary for observing CP violation. Each stage of the neutrino factory (high power proton beam generation, pion production and collection, muon manipulation and acceleration) is technologically challenging and must be optimized very carefully in order to overcome the low proton-to-pion conversion (of the order of 1%). Studies and experimental activities are going on in Japan, Europe and in the Unite States. Neutrino factories activities bring together accelerator and particle physicists, as the interplay between these two disciplines is very strong at almost every stage of the machine. This synergy is reflected in the collection of articles in this newsletter. After an introduction on the physics motivation, a description of the KEK activities and a report on FFAG acceleration comes a collection of articles describing ionization cooling from three points of view (beam dynamics, experimental and analytical). The section is closed by a description of the experiment HARP which will provide an important input to the neutrino factory design by measuring, amongst others, the spectrum of the pions produced by a proton beam of varying energy on different target material.
The activity section contains the important results at the TWAC facility at ITEP where some 1010 C6+ ions have been successfully accumulated and several reports from workshop and conferences. The final section recalls the upcoming ICFA beam dynamics workshops (the 28th, 29th and 30th and the 12th mini-workshop ) and other workshops related to cooling (COOL03) and neutrinos (Nufact03). Finally in appendix there are two tables : the first listing the simulation codes used for slow extraction design and analysis and the second with the status of instrumentation for existing and planned machines around the world. They were compiled at the 10th and 11th ICFA mini workshop, respectively.
