Advanced Accelerator Research at BNL

S.J. Brooks {sbrooks@bnl.gov}, D. Trbojevic, G. Mahler, Brookhaven National Laboratory, Upton, NY, USA

This poster presents two emerging accelerator technologies studied at BNL Collider-Accelerator Department.
One is the use of high-field permanent magnets, which have become commonplace in recent decades, as the main bending and focussing field of an accelerator, with fields up to 1.85 Tesla here.  These are used in a proposed hadron therapy facility, where a fixed-field accelerator (FFA) design allows proton beams to ramp from 10-250MeV without changes in the magnetic field (the beam orbit shifts instead).  Magnetic inductance effects do not have to be overcome in an FFA, leading to faster machine cycle rates of ~500Hz.  This allows ultra-high dose rate or FLASH therapy, with sub-second treatment times that benefit patient outcomes.
The second technology is the production of ultra-low emittance ion bunches via laser Doppler cooling.  These bunches have typical temperatures of a few milli-Kelvin and emittances roughly 10^5 times smaller than typical plasma ion sources.  Ions at this temperature form a solid lattice or "Coulomb crystal".  Simulations show these solid crystals can be transported for thousands of turns in the BNL Booster synchrotron, even without cooling, if quadrupole settings are chosen correctly.  The small emittance in X, Y and Z implies a potential 10^15 increase in density of focal points formed from crystalline bunches, with a path to creating bulk nuclear density matter (neutronium) at LHC-scale energies.