MSU, East Lansing, Michigan, USA
Fermilab, Batavia, Illinois, USA
Northern Illinois University, DeKalb, Illinois, USA
The main goal of the Muon g-2 Experiment at Fermilab (E989) is to measure the muon anomalous magnetic moment (a, also dubbed as the "anomaly’’) to unprecedented precision. This new measurement will allow to test the completeness of the Standard Model (SM) and to validate other theoretical models beyond the SM. Simulations of the beamlines from the pion production target to the entrance of the g-2 Storage Ring using COSY INFINITY contribute to the understanding and characterization of the muon beam production in relation to the statistical and systematics uncertainties of the E989 measurement. The effect of nonlinearites from fringe fields and high-order contributions on the beam delivery system performance are considered, as well as interactions with the beamline elements apertures, particle decay channels, spin dynamics, and beamline misalignments.
TUPAF11
Fermilab, Batavia, Illinois, USA
MSU, East Lansing, Michigan, USA
Illinois Institute of Technology, Chicago, Illlinois, USA
The development of new types of accelerators that allow wide choices of parameters, promote complicated fields, and often need to efficiently handle very large emittance beams requires the availability of new simulation environments to design and accurately predict operation. This is particularly true of Fixed-field accelerators, FFAs, which apply arbitrary-order fields - both alternating gradient, strong focusing - but also weak-focusing cyclotrons. This is especially applicable at medium-to-high energy combined with high intensity (mA currents). Synchrotron and cyclotron codes are generally inadequate to simulate accurately the performance of these strong-focusing fixed-field accelerators, particularly the new breed of non-scaling machines which have difficult, high-order fringe-field and edge-angle effects. One well-supported code, COSY INFINITY (COSY) is particularly suitable for accurate, high-order descriptions of accelerators. New tools have been developed in COSY INFINITY to address and accurately represent complex fixed-field machines in both a sector and spiral sector footprint. A description, application, and comparison of these tools with fields from magnet lattice design is presented.
MSU, East Lansing, Michigan, USA
We consider semi-infinite electrostatic deflectors with plates of different thickness, including plates with rounded edges, and we calculate their electrostatic potential and field using conformal mappings. To validate the calculations, we compare the fringe fields of these electrostatic deflectors with fringe fields of finite electrostatic capacitors, and we extend the study to fringe fields of adjacent electrostatic deflectors with consideration of electrostatic induction, where field falloffs of semi-infinite electrostatic deflectors are slower than exponential and thus behave differently from most magnetic fringe fields. Building on the success with electrostatic deflectors, we develop a highly accurate and fully Maxwellian conformal mappings method for calculation of main fields of electrostatic particle optical elements. A remarkable advantage of this method is the possibility of rapid recalculations with geometric asymmetries and mispowered plates. We use this conformal mappings method to calculate the multipole terms of the high voltage quadrupole used in the storage ring of the Muon g-2 Experiment (FNAL-E-0989). Completing the methodological framework, we present a method for extracting multipole strength falloffs of a particle optical element from a set of Fourier mode falloffs. We calculate the quadrupole strength falloff and its effective field boundary (EFB) for the Muon g-2 quadrupole, which has explained the experimentally measured tunes, while simple estimates based on a linear model exhibited discrepancies up to 2%.