Publications: Internal Task note

Author(s) :A. Bechtold, M. Benedikt, F. Borgnolutti, E. Bouquerel, L. Bozyk, J. Bruer, A. Chancé, P. Delahaye, A. Fabich, S. Hancock, C. Hansen, E. Jensen, A. Källberg, M. Kirk, A. Lachaize, M. Lindroos, M. Magistris, A. Mueller, J. Payet, H. Podlech, P. Puppel, M. Silari, A. Simonsson, P. Spiller, S. Stadlmann, A. Tkatchenko, S. Trovati, V. Vlachoudis, and E. Wildner

The Beta-Beam project is a concept of large scale facility that aims at providing pure electronic neutrino and antrineutrino beams for the measurement of nu_e --> nu_µ oscillations, offering unprecedented sensitivity for detection of the Theta_13 mixing angle and CP violating phase. In the scenario presented in different publications [1-3], a Beta-Beam facility could be advantageously placed at CERN making use of the PS and SPS for accelerating the beta-decaying, neutrino-emitting beams to a Lorentz gamma of 100. Intense beams of 6He and 18Ne would be produced using the so-called “isotope-separation on line” ISOL method in a facility of the scale of EURISOL. The synergy between the two projects was pointed out in [4]. The task 12 of the EURISOL design study aimed at producing a conceptual design report for the accelerator chain of a EURISOL/CERN-baseline Beta-Beam facility. This document summarizes the achievements made during the time of the study and constitutes the final conceptual report of the beta-beam facility. References [1] B. Autin, M. Benedikt, M. Grieser, S. Hancock, H. Haseroth, A. Jansson, U. Köster, M. Lindroos, S. Russenschuck and F. Wenander, "The acceleration and storage of radioactive ions for a neutrino factory", CERN/PS 2002-078 (OP), Nufact Note 121, J. Phys. G 29 (2003) 1785-1796 and long internal CERN version, PS/OP/Note 2002-181. [2] M.Mezzetto, "Physics reach of the beta-beam", J. Phys. G: Nucl. Part. Phys. 29 (2003) 1771–1776 [3] J. Bouchez, M. Lindroos and M. Mezzetto, 5th International Workshop on Neutrino Factories and Superbeams; NuFact 03. AIP Conference Proceedings, Volume 721, pp. 37-47 (2004). [4] Letter of Intent: FP6 Design Study for a beta-beam facility , September, 2003

Author(s) :A. Bechtold, M. Benedikt, F. Borgnolutti, E. Bouquerel, L. Bozyk, A. Chancé, P. Delahaye, A. Fabich, S. Hancock, C. Hansen, E. Jensen, A. Kaellberg, M. Kirk, A. Lachaize, M. Lindroos, M. Magistris, A. Mueller, J. Payet, P. Puppel, P. Spiller, A. Tkatchenko, S. Trovati, V. Vlachoudis

The Beta-Beam project is a concept of large scale facility that aims at providing pure electronic neutrino and antrineutrino beams for the measurement of nu_e --> nu_µ oscillations, offering unprecedented sensitivity for detection of the Theta_13 mixing angle and CP violating phase. In the scenario presented in different publications [1-3], a Beta-Beam facility could be advantageously placed at CERN making use of the PS and SPS for accelerating the beta-decaying, neutrino-emitting beams to a Lorentz gamma of 100. Intense beams of 6He and 18Ne would be produced using the so-called “isotope-separation on line” ISOL method in a facility of the scale of EURISOL. The synergy between the two projects was pointed out in [4]. The task 12 of the EURISOL design study aimed at producing a conceptual design report for the accelerator chain of a EURISOL/CERN-baseline Beta-Beam facility. This document summarizes the achievements made during the time of the study and constitutes the final conceptual report of the beta-beam facility. References [1] B. Autin, M. Benedikt, M. Grieser, S. Hancock, H. Haseroth, A. Jansson, U. Köster, M. Lindroos, S. Russenschuck and F. Wenander, "The acceleration and storage of radioactive ions for a neutrino factory", CERN/PS 2002-078 (OP), Nufact Note 121, J. Phys. G 29 (2003) 1785-1796 and long internal CERN version, PS/OP/Note 2002-181. [2] M.Mezzetto, "Physics reach of the beta-beam", J. Phys. G: Nucl. Part. Phys. 29 (2003) 1771–1776 [3] J. Bouchez, M. Lindroos and M. Mezzetto, 5th International Workshop on Neutrino Factories and Superbeams; NuFact 03. AIP Conference Proceedings, Volume 721, pp. 37-47 (2004). [4] Letter of Intent: FP6 Design Study for a beta-beam facility , September, 2003

Author(s) :A. Chancé, E. Bouquerel, S. Hancock, E. Jensen and J. Payet

The study of the neutrino oscillation between its different flavours needs pure and very intense fluxes of high energy, well collimated neutrinos with a well determined energy spectrum. A dedicated machine seems to be necessary nowadays to reach the required flux. A new concept based on the β-decay of radioactive ions which were accelerated in an accelerator chain was then proposed. After ion production, stripping, bunching and acceleration, the unstable ions are then stored in a racetrack-shaped superconducting decay ring. Finally, the ions are accumulated in the decay ring until being lost. The incoming beam is merged to the stored beam by using a specific RF system, which will be presented here. We propose here to study some aspects of the decay ring, such as its optical properties, its RF system or the management of the losses which occur in the ring (mainly by decay or by collimation).

Author(s) :Antoine LACHAIZE André TKATCHENKO

During the last two years, several upgrades of the initial baseline scenario were studied with the aim of increasing the average intensity of ion beams in the accelerator chain of the Beta Beam complex. This is the reason why the Rapid Cycling Synchrotron (RCS) specifications were reconsidered many times [1], [2], [3]. General considerations on the optical design were presented at the Beta Beam Task Meetings held at CERN and at Saclay in 2005 [4]. More detailed beam optics studies were performed during the next months. Lattices, RF system parameters, multi-turn injection scheme, fast extraction, closed orbit correction and chromaticity correction systems were proposed for different versions of the RCS [5], [6], [7]. Finally, the RCS specifications have stabilized in November 2006 after the fourth Beta Beam Task Meeting when it was decided to fix the maximum magnetic rigidity of ion beams to 14.47 T.m (3.5 GeV equivalent proton energy) and to adopt a ring physical radius of 40 m in order to facilitate injection in the CERN PS. The present report describes this RCS new design which is based on the results of the previous studies and which fulfils all updated requirements.

Author(s) :M. Benedikt, S. Hancock

Ion acceleration in the PS and SPS is a routine operation since many years. Different ion types from light ions such as sulphur up to heavy ions such as lead have been accelerated. This document summarizes the results of the study realized within FP6 for the acceleration of the Beta-Beam nuclides 6He and 18Ne.

Author(s) :A. Tkatchenko, IPN Orsay

First considerations are given on the Rapid Cycling Synchrotron of the Beta-Beam facility. Presentation at the first task meeting, 14/04/2005.

Author(s) :A.Lachaize and A.Tkatchenko CNRS, IPNO, France

The Rapid Cycling Synchrotron of the Beta-Beam facility has been designed to operate with horizontal and vertical tunes between 6 and 7 in order to avoid systematic resonances up to the fourth order. Nevertheless, unavoidable magnet imperfections may excite non systematic second order resonances which may pertub particle motion. In this paper an Hamiltonian treatment based on a well established formalism [1-3] is used to analyze the resonance excitation and to suggest correction schemes minimizing their effects. [1] A. Schoch. Theory of linear and non linear perturbations of betatron oscillations in alternating gradient synchrotrons. CERN 52-21, 1958. [2] G. Guignard. A general treatment of resonances in accelerators. CERN 78-11, 1978. [3] J-L. Laclare, G. Leleux, and A. Tkatchenko. Resonnances quadrupolaires- aleatoires quadrupolaires et corrections. DSS-GERS- 74-91/TP-06, 1974.

Author(s) :M. Benedikt A. Fabich S. Hancock M. Lindroos

The previous “version”, numbered 2 [1] and published in summer 2005, describes the EURISOL baseline parameters and intensities based on an RCS injection energy of 2.5 GeV proton equivalent. In the course of the past two years, the RCS ejection energy has been upgraded to overcome potential space charge difficulties. Maintaining the “top-down” analysis for the intensities along the accelerator chain, the database of baseline parameters [2] has been updated. [1] M. Benedikt, A. Fabich, S. Hancock and M. Lindroos, "The EURISOL Beta-beam facility parameter and intensity values, version 2, July 2005", EURISOL DS/TASK12/TN‑05‑03 (2005). [2] http://cern.ch/beta-beam-parameters/

Author(s) :Elena Wildner/ CERN-AT-MCS, Frederick Jones/ TRIUMF (Canada), Francesco Cerutti/ CERN-AB-ATB

This note describes studies of energy deposition in superconducting magnets from secondary ions in the “beta beam” decay ring as described in the base-line scenario of the EURISOL Beta Beam Design Study. The lattice structure proposed in the Design Study has absorber elements inserted between the superconducting magnets to protect the magnet coils. We describe an efficient and small model made to carry out the study. The specially developed options in the beam code “ACCSIM” to track largely off-momentum particles has permitted to extract the necessary information to interface the transport and interaction code “FLUKA” with the aim to calculate the heat deposition in the magnets and the absorbers. The two beta emitters 18Ne10+ and 6He2+ used for neutrino and anti-neutrino production and their daughter ions have been tracked. The absorber system proposed in the Design Study is efficient to intercept the ions decayed in the arc straight sections as foreseen, however, the continuous decay in the dipoles induce a large power deposition in the magnet mid-plane. This suggests a different magnet design, like an open mid-plane magnet structure (such a magnet has been designed for this purpose) and/or protecting liners inside the magnets. The power deposited in the superconducting magnets is, with the layout proposed in the Design Study, below the recommended value of 10 W/m. The work described was done in collaboration between CERN and TRIUMF, Canada's national laboratory for particle and nuclear physics, during a 2 month’s visit of one person at TRIUMF. The work was supported by the European Isotope Separation On-Line Radioactive Ion Beam Facility, EURISOL, in which “beta beams” is one of the work packages

Author(s) :A. Lachaize and A. Tkatchenko

During the last two years, several upgrades of the initial baseline scenario were studied with the aim of increasing the average intensity of ion beams in the accelerator chain of the Beta Beam complex. This is the reason why the Rapid Cycling Synchrotron (RCS) specifications were reconsidered many times. General considerations on the optical design were presented at the Beta Beam Task Meetings held at CERN and at Saclay in 2005 (http://beta-beam.web.cern.ch/beta-beam/). More detailed beam optics studies were performed during the next months. Lattices, RF system parameters, multi-turn injection scheme, fast extraction, closed orbit correction and chromaticity correction systems were proposed for different versions of the RCS. Finally, the RCS specifications have stabilized in November 2006 after the fourth Beta Beam Task Meeting when it was decided to fix the maximum magnetic rigidity of ion beams to 14.47 T.m (3.5 GeV equivalent proton energy) and to adopt a ring physical radius of 40 m in order to facilitate injection in the CERN PS. The present report describes this RCS new design which is based on the results of the previous studies and which fulfils all updated requirements.