| Paper | Title | Page |
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| MOPAB190 | An 8 GeV Linac as the Booster Replacement in the Fermilab Power Upgrade | 643 |
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Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. Increasing the Main Injector (MI) beam power above ~1.2 MW requires replacement of the 8 GeV Booster by a higher intensity alternative. Previously, rapid-cycling synchrotron (RCS) and Linac solutions were considered for this purpose. In this paper, we consider the Linac version that produces 8 GeV H− beam for injection into the Recycler Ring (RR) or Main Injector (MI). The Linac takes ~1 GeV beam from the PIP-II Linac and accelerates it to ~2 GeV in a cw SRF linac, followed by a ~2-8 GeV pulsed linac using 1300 MHz cryomodules. The linac components incorporate recent improvements in SRF technology. The linac configuration and beam dynamics requirements are presented. Injection options are discussed. Research needed to implement the Booster replacement is described. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB190 | |
| About • | paper received ※ 15 May 2021 paper accepted ※ 28 May 2021 issue date ※ 10 August 2021 | |
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| WEPAB216 | 6D Simulations of PIP-II Booster Injection | 3138 |
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Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. The PIP-II superconducting linac will deliver 2 mA average H- beam current at 800 MeV to the existing Booster synchrotron over a period of 0.55 ms (285 turns). As a result, the injected beam power will quadruple to 17 kW. Safe operation at the increased beam power implies careful attention to the origin, magnitude, and distribution of both controlled and uncontrolled losses. Uncontrolled losses are due to neutral ions in excited states stripped in downstream magnets and large angle scattered protons from parasitic foil hits. The relative magnitudes of these loss mechanisms is used to determine the optimal foil thickness. A transverse painting scheme involving closed orbit motion will be used to mitigate space charge effects and minimize parasitic foil hits. Using a detailed full 6D simulation of the injection process, we compute large angle scattering losses and compare results to back of the envelope estimates. We investigate possible impact of space charge on the emittance and beam distribution both during and at the conclusion of the injection period. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB216 | |
| About • | paper received ※ 20 May 2021 paper accepted ※ 24 June 2021 issue date ※ 10 August 2021 | |
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| WEPAB221 | H0 Stark Stripping and Component Irradiation in Fermilab Booster | 3142 |
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Funding: Work supported by Fermi Research Alliance, LLC under contract no. DE-AC02-07CH11359 In foil stripping of H− some fraction of the emerging neutral H0 will be in excited states, which can then strip through the Stark effect in the magnetic field of the downstream orbit bump magnet. The resultant H+ will experience a depleted net kick compared to protons emerging from the foil and will track on trajectories different from the nominal circulating beam. This will lead to irradiation of downstream machine components. An analysis of these processes is of particular importance looking forward to the much higher beam power of the Fermilab PIP-II era. This study investigates where these errant protons will be lost, how much power is deposited, and whether this will be a shielding concern. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB221 | |
| About • | paper received ※ 11 May 2021 paper accepted ※ 09 June 2021 issue date ※ 20 August 2021 | |
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| THPAB158 | BEAM COLLIMATION IN THE PIP-II LINAC TO BOOSTER TRANSFER LINE | 4068 |
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Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics. The new PIP-II superconducting linac will deliver a 2 mA average H- beam to the existing Booster synchrotron. The injected beam is accumulated by charge exchange over approximately 300 turns; phase space painting is used to mitigate space charge effects. To limit the power load on the internal waste beam absorber from the transverse tails of the H− distribution missing the foil, the beam will be collimated in both planes in the linac to Booster transfer line using compact collimators of a novel design. Both the number of parasitic hits and the fraction of the beam missing the foil are sensitive functions of the H− beam centroid position with respect to the edge of the foil. The positioning of the collimation is constrained by the availability of suitable space in the transfer line lattice, by specifics of the collimator design, by the phase space orientation at the collimator, and by the betatron phase advance to the foil needed to achieve proper orientation of the spatial distribution at the injection point. In this contribution, we describe the procedure by which collimator positions were optimized. We then discuss the expected performance of the overall system. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB158 | |
| About • | paper received ※ 04 June 2021 paper accepted ※ 02 July 2021 issue date ※ 26 August 2021 | |
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