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| MOPPC023 | Polarization Transmission at RHIC, Numerical Simulations | 178 |
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| Ray-tracing methods, using the computer code Zgoubi, have proven efficient for beam and spin dynamics simulations in RHIC (see earlier PAC and IPAC publications). More simulations and results are being produced, including spin code benchmarking and cross-checking, effects of strongest resonances and working point on transport of polarization, polarization with Run 9 and Run 11 measured ramp orbit and optics, polarization profiles, etc. The numerical methods involved are recalled, a status of the work is given. | ||
| MOPPC024 | Modelling of the AGS Using Zgoubi - Status | 181 |
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| A computer model, based on the ray-tracing code Zgoubi, is being developed in view of on-line simulation of the RHIC injector AGS, and of beam and spin dynamics simulations and studies in the presence of the cold and warm helical partial snakes. A status of this work is given here. | ||
| MOPPC025 | RHIC Polarized Proton Operation in Run 12 | 184 |
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| Successful RHIC operation with polarized protons requires meeting demanding and sometimes competing goals for maximizing both luminosity and beam polarization. In Run 12 we sought to fully integrate into operation the many systems that were newly commissioned in Run 11 as well as to enhance collider performance with incremental improvements throughout the acceleration cycle. For luminosity maximization special attention was paid to several possible source of emittance dilution along the injector chain, in particular to optical matching during transfer between accelerators. Possible sources of depolarization in the AGS and RHIC were also investigated including the effects of local coupling and low frequency (10 Hz) oscillations in the vertical equilibrium orbit during the RHIC ramp. The results of a fine storage energy scan made in an effort to improve store polarization lifetime are also reported in this note. | ||
| MOPPD026 | A Superconducting Ring Cyclotron for the DAEδALUS Experiment | 421 |
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Funding: Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud. The experiment DAEδALUS*, proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector** and of a booster ring cyclotron has been proposed***. The booster Superconducting Ring Cyclotron is able to accelerate a H2+ molecule beam up to 800 MeV/n with a peak current of 10 mA and average power higher than 1.6 MW. To simplify the design of the superconducting magnetic coils, to minimize the radial force shift and to increase the room to host the RF cavities, the previous study has been updated increasing the injection energy of the H2+ and also the injection energy. The updated study on the magnetic sector configuration, on the superconducting coils and the magnetic forces are presented. The isochronous magnetic field, the beam dynamics along the injection and extraction path and during the acceleration are presented, too. * J. Alonso et al., Jun2010 e-Print: arXiv:1006.0260 ** L. Calabretta, Proc. IPAC 2011, WEPS073 (2011). *** L. Calabretta, Cyclotrons 2010, Lanzhou. |
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| TUPPC062 | Transfer of Polarized 3He Ions in the AtR Beam Transfer Line | 1317 |
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Funding: Work supported by the US Department of Energy In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will also facilitate the collisions of electrons with polarized 3He ions. The AGS is the last acceleration stage of ions before injection into one RHIC for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized 3He ions from AGS into one of the RHIC’s collider rings. In this paper we investigate the extraction energy of the polarized 3He ions from the AGS which will optimize the polarization of 3He ions injected into RHIC. Some of the peculiarities (interleaved horizontal and vertical bends) of the AtR line's layout may degrade this spin matching of the polarized 3He ions. We will also discuss possible simple modifications of the AtR line to accomplish a perfect “spin matching” of the injected 3He beam with that of the stable spin direction at the injection point of the RHIC ring. |
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| TUPPC101 | A Model of the AGS Based on Stepwise Ray-Tracing Through the Measured Field Maps of the Main Magnets | 1395 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Two dimensional mid-plane magnetic field maps of two of the main AGS magnets were produced, from Hall probe measurements, for a series of different current settings. The analysis of these data yielded the excitation functions and harmonic coefficients of the main magnets [BNL TN 424 & TN 429] which have been used so far in all the models of the AGS. The constant increase of computation power makes it possible today to directly use stepwise ray-tracing through these measured field maps with a reasonable computation time. We describe in detail how these field maps have allowed generation of models of the 6 different types of AGS main magnets, and how they are being handled with the Zgoubi ray-tracing code. We give and discuss a number of results so obtained regarding both beam and spin dynamics in the AGS, and provide comparisons with other numerical and analytical modeling methods. |
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| THPPR063 | 1 GeV CW Nonscaling FFAG for ADS, and Magnet Parameters | 4118 |
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| Multi-MW proton driver capability remains a challenging, critical technology for many core HEP programs, particularly the neutrino ones such as the Muon Collider and Neutrino factory, and for next generation energy applications such as Accelerator Driven Subcritical Reactors (ADS) and Accelerator Transmutation of Waste for nuclear power and waste management. Work is focused almost exclusively on an SRF linac, as, to date, no re-circulating accelerator can attain the 10-20 MW capability necessary for the nuclear applications. Recently, the concept of isochronous orbits has been explored and developed for nonscaling FFAGs using powerful new methodologies in FFAG accelerator design. The FFAG can remain isochronous beyond the energy reach of cyclotrons and with fixed magnetic fields and strong focusing coupled to recent advances in tune stability, dynamic aperture, and footprint, serious study is underway on a potential application to the ADS problem. Work is progressing on a stable, high intensity, 0.25-1GeV isochronous FFAG. Development and studies of novel magnets with the nonlinear radial fields required to support isochronous operation are reported here. | ||
| THPPR064 | MW-class 800 MeV/n H2+ SC-Cyclotron for ADC application, Design Study and Goals | 4121 |
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| A megawatt class isochronous cyclotron is a potential candidate for accelerator driven systems, as in the subcritical-fission molten-salt reactor application. A scheme for a 800 MeV/nucleon cyclotron accelerating molecular H2+ has been derived from on-going proton driver design studies for neutrino beam production. The present paper reports on beam dynamics studies regarding that cyclotron, exploiting its superconducting coil magnetic sector OPERA field map. These studies are aimed at assessing lattice properties as accelerated orbit, phase oscillations, tunes, beam envelopes and other resonance effects. | ||