| Paper | Title | Page |
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| ROAA001 | DAFNE Operation and Plans for DAFNE2 | 112 |
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| The e+e- collider DAFNE, a 1.02 Gev c.m. Phi-factory, has exceeded 1.2 1032 cm-2s-1 peak luminosity with 7.5 pb-1 maximum daily integrated luminosity. At the present performance the physics program of the three main experiments DEAR, FINUDA and KLOE will be completed by mid 2007. In this paper we describe the steps which have led to the luminosity improvement and present proposals for the upgrade of the collider towards higher energy and/or luminosity. The main accelerator issues on which we are planning to rely for this purpose, such as lattices with negative momentum compaction, strong RF focusing, design of high field magnets and Linac upgrade, are discussed in detail. | ||
| ROAA002 | CESR-c: Performance of a Wiggler-Dominated Storage Ring | 189 |
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Funding: Work supported by the U.S. National Science Foundation. CESR-c operates now as a Wiggler-Dominated Storage Ring extending the lowest operating energy to 1.5GeV/beam. To improve beam stability at low energy, 12 super-ferric wiggler magnets with total length of 15m and 2.1T maximum field were installed in the ring. They cause ~90% of total beam radiation lost and increase radiation damping rate by factor 10 from ~3 to 40 Hz. However, the field of the wiggler magnets not only initiates the radiation, but potentially affects beam dynamics. The latter was an issue of a great concern from the planning the CESR-c project. In this paper we describe general performance of CESR-c and report the results of an experimental study on some aspects of beam dynamics. Comparisons are made between the experimental data and the model prediction. We find that all parameters, which are critically dependent on wigglers, such as beam properties and ring nonlinearity, are in good agreement with those calculated from the model. This validates the ring and wiggler models and justifies our design and production technique of the magnets. The experience we obtained will be extremely useful in future work on linear collider damping rings. |
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| ROAA003 | Proposal of an Experiment on Bunch Length Modulation in DAFNE | 336 |
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| Obtaining very short bunches is a challenge for colliders and Coherent Synchrotron Radiation sources as well. The modulation of the bunch length in a strong RF focusing regime has been proposed, corresponding to a large value of the synchrotron tune. A ring structure where the dependence of the longitudinal position of a particle on its energy (R56) along the ring oscillates between large positive and negative values can produce a bunch length modulation. The synchrotron frequency can be tuned both by means of the rf voltage and by the integral of R56, down to the limit of zero value corresponding to the isochronicity condition. We present here the proposal of bunch length modulation along the DAFNE rings. Its lattice can be tuned to positive or negative momentum compaction, or to structures in which the two arcs are alternately set to positive/negative integrals of R56. With the proposed installation of an extra RF system at 1.3 GHz, experiments on bunch length modulation both in the high and low synchrotron tune regimes can be realized. | ||
| ROAA004 | MICE: The International Muon Ionisation Cooling Experiment | 398 |
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| Muon storage rings have been proposed for use as sources of intense high-energy neutrino beams and as the basis for multi-TeV lepton-antilepton colliding beam facilities. To optimise the performance of such facilities is likely to require the phase-space compression (cooling) of the muon beam prior to acceleration and storage. The short muon-lifetime makes it impossible to employ traditional techniques to cool the beam while maintaining the muon-beam intensity. Ionisation cooling, a process in which the muon beam is passed through a series of liquid hydrogen absorbers followed by accelerating RF-cavities, is the technique proposed to cool the muon beam. The international Muon Ionisation Cooling Experiment (MICE) collaboration has been formed to carry out a muon-cooling demonstration experiment, and its proposal to Rutherford Appleton Laboratory has been approved. The MICE cooling channel, the instrumentation and the implementation at the Rutherford Appleton Laboratory is described together with the predicted performance of the channel and the measurements that will be made. | ||
| ROAA005 | Recent Innovations in Muon Beam Cooling and Prospects for Muon Colliders | 419 |
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Funding: This work was supported in part by DOE SBIR/STTR grants DE-FG02-02ER86145, 03ER83722, 04ER84015, 04ER86191, and 04ER84016. A six-dimensional(6D)cooling channel based on helical magnets surrounding RF cavities filled with dense hydrogen gas* is used to achieve the small transverse emittances demanded by a high-luminosity muon collider. This helical cooling channel**(HCC) has solenoidal, helical dipole, and helical quadrupole magnetic fields to generate emittance exchange. Simulations verify the analytic predictions and have shown a 6D emittance reduction of over 3 orders of magnitude in a 100 m HCC segment. Using three such sequential HCC segments, where the RF frequencies are increased and transverse dimensions reduced as the beams become cooler, implies a 6D emittance reduction of almost six orders of magnitude. After this, two new post-cooling ideas can be employed to reduce transverse emittances to one or two mm-mr, which allows high luminosity with fewer muons than previously imagined. In this report we discuss the status of and the plans for the HCC simulation and engineering efforts. We also describe the new post-cooling ideas and comment on the prospects for a Higgs factory or energy frontier muon collider using existing laboratory infrastructure. *R. P. Johnson et al. LINAC2004, www.muonsinc.com/TU203.pdf. **Y. Derbenev and R.P. Johnson, Submitted to PRSTAB, http://www-mucool.fnal.gov/mcnotes/public/pdf/muc0284/muc0284.pdf. |