Speaker
Description
A variable wedge system is being developed for the FRIB-Advanced Rare Isotope Separator (ARIS) facility to provide flexible control of beam energy loss. This research evaluates two parallel strategies: a multi-material six-piece solid wedge system and a liquid-filled wedge system. For the solid wedge, the control model and optimization algorithms have been developed and verified, with systematic testing confirming automated control across a 1–20 mrad range. Current efforts focus on exploring sub-mrad regimes (<1 mrad). To address fabrication limitations associated with very thin wedges, a multi-material method was developed in which materials with different densities are selected while maintaining constant areal density. This approach scales the effective thickness range by the density ratio, improving achievable thickness resolution and reducing deviations between calculated and experimentally achievable equivalent wedge configurations. Computational efficiency was further improved by using an L_∞trajectory solver to minimize total actuator displacement. This framework is currently being integrated into the fragment separator simulation code LISE++. In parallel, a liquid-filled wedge model was developed, utilizing a bellows-integrated cylindrical housing to enable continuous density tuning alongside adjustable wedge geometry. Together, these developments provide a robust basis for enhancing rare isotope beam delivery at FRIB.
Funding Agency
U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Award No. DE-SC0023633, and Facility for Rare Isotope Beams (FRIB).
Footnotes
- M. Hausmann, A.M. Aaron, A.M. Amthor, et al., "Design of the Advanced Rare Isotope Separator ARIS at FRIB," Nucl. Instrum. Methods Phys. Res. B, Vol. 317, Part B, 2013, pp. 349-353, ISSN 0168-583X.
** J. Hwang, S. Michimasa, S. Ota, et al., "Angle-tunable wedge degrader for an energy-degrading RI beamline," PTEP 2019 (2019) 4, 043D02, DOI: 10.1093/ptep/ptz028.
| Paper status | Resubmitted proceeding files received and assigned to an editor. Accepted. |
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