Status of muon collider research and development and future plans

Abstract

The status of the research on muon colliders is discussed and plans are outlined for future theoretical and experimental studies. Besides work on the parameters of a 3-4 and 0.5 TeV center-of-mass (COM) energy collider, many studies are now concentrating on a machine near 0.1 TeV (COM) that could be a factory for the s-channel production of Higgs particles. We discuss the research on the various components in such muon colliders, starting from the proton accelerator needed to generate pions from 1098-4402͞99͞2(8)͞081001(73)$15.00 © 1999 The American Physical Society 081001-1 PRST-AB 2 CHARLES M. ANKENBRANDT et al. 081001 (1999) a heavy-Z target and proceeding through the phase rotation and decay (p ! m n m ) channel, muon cooling, acceleration, storage in a collider ring, and the collider detector. We also present theoretical and experimental R&D plans for the next several years that should lead to a better understanding of the design and feasibility issues for all of the components. This report is an update of the progress on the research and development since the feasibility study of muon colliders presented at the Snowmass '96

Beam dynamics of muon acceleration for neutrino factory

“…A neutrino factory [1] is aimed to produce narrow neutrino beams via decay of muons in long straight sections of a storage ring. As illustrated schematically in Figure 1, a proposed muon accelerator complex features a 0.2-to-2.8 GeV straight pre-accelerator linac and a 2.8-to-20 GeV four-pass recirculating linac accelerator (RLA).…”

Rotating band pion production targets for muon colliders and neutrino factories

“…These pion yields and the predicted phase space densities are almost identical to the best predicted yields for the exotic liquid mercury jet targets that are also under consideration [4] for muon colliders and neutrino factories. Optimization studies [13,9] for both mercury jet and band targets further suggest that such yields are rather close to the optimum that could be obtained even for a low power proton beam, thus satisfying the fourth of the design goals stated in section 2.…”

“…The pion secondaries spiral along the solenoidal magnetic channel before decaying into the muon bunches needed for cooling, acceleration and injection into the collider ring. The radius of the solenoidal channel, 7.5 cm, and the magnetic field strength, 20 Tesla, are those commonly assumed for recent muon collider studies [9]. The design modification specific to this particular geometry concerns the provision of entry and exit ports for the target band.…”

“…It should be emphasized that such details as the rollers and cooling setup are shown only schematically and that no concerted effort has been put into their design or layout. The cupronickel target band is enclosed in a 20 Tesla solenoidal magnetic pion capture magnet whose general design has previously been studied [9] by the Muon Collider Collaboration. The pion secondaries spiral along the solenoidal magnetic channel before decaying into the muon bunches needed for cooling, acceleration and injection into the collider ring.…”

Recent Results from the MERIT Experiment

“…The scenarios for a muon collider [1] or a neutrino factory [2] require a target which can accept an intense 4-MW-class proton beam. This beam is desired in order to produce a copious number of pions which are subsequently conducted in a decay channel which permits the collection of the muon decay products.…”