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Makino, K.

Publications and source records attributed to Makino, K..

Dynamical simulations of the Muon Campus at Fermilab

The Muon Campus at Fermilab is a system through which muons are delivered to the storage ring of the Muon g-2 Experiment (E989). It consists of a set of 1 km beamlines that transport and prepare a highly polarized muon beam out of secondaries produced downstream a target station. Realistic simulations of this beam delivery system (BDS) using COSY INFINITY, and presented here, contribute to the understanding and characterization of the muon beam production in relation to the statistical and systematic uncertainties of the E989 measurement, intended to be smaller than 0.14 parts per million to achieve the goals of the experiment. The impact of nonlinearities from fringe fields and high-order contributions on the BDS performance are presented, as well as detailed studies of the interactions between secondaries and the beamline elements apertures, particle decay channels, spin dynamics and beamline misalignments.

43 PARTICLE ACCELERATORS↗

Muon loss rates from betatron resonances at the Muon g – 2 Storage Ring at Fermilab

The Muon g–2 Experiment at Fermilab (E989) is directed toward measuring the muon magnetic anomaly, a μ = (g–2)/2, with total statistical and systematic errors of 0.14 ppm. Here, this new measurement will serve as strong probe of effects of as yet undiscovered particles beyond the Standard Model (SM), and perhaps validate or disprove other theoretical models beyond the SM. Of special interest is the reduction of muon losses from the storage ring to achieve the precision needed at the Muon g–2 Experiment.

43 PARTICLE ACCELERATORS↗

Accurate Taylor transfer maps for large aperture iron dominated magnets used in charged particle separators and spectrometers

For high-resolution separators like the projected Super-FRS at FAIR, an adapted and accurate ion-optical model considering realistic $B$-dependent magnet parameters is crucial in achieving the desired parameters (e.g. resolution) and to enable a fast optimization. Starting from the magnetic field measurements and simulations, rigidity-dependent Taylor transfer maps are generated for the Super-FRS preseparator dipole magnets. The effects of the magnetic saturation in the steel yoke on the image aberrations are analyzed.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Active control of bright electron beams with RF optics for femtosecond microscopy

A frontier challenge in implementing femtosecond electron microscopy is to gain precise optical control of intense beams to mitigate collective space charge effects for significantly improving the throughput. Here, we explore the flexible uses of an RF cavity as a longitudinal lens in a high-intensity beam column for condensing the electron beams both temporally and spectrally, relevant to the design of ultrafast electron microscopy. Through the introduction of a novel atomic grating approach for characterization of electron bunch phase space and control optics, we elucidate the principles for predicting and controlling the phase space dynamics to reach optimal compressions at various electron densities and generating conditions. We provide strategies to identify high-brightness modes, achieving ∼100 fs and ∼1 eV resolutions with 106 electrons per bunch, and establish the scaling of performance for different bunch charges. These results benchmark the sensitivity and resolution from the fundamental beam brightness perspective and also validate the adaptive optics concept to enable delicate control of the density-dependent phase space structures to optimize the performance, including delivering ultrashort, monochromatic, high-dose, or coherent electron bunches.

43 PARTICLE ACCELERATORS↗

A Storage Ring Experiment to Detect a Proton Electric Dipole Moment

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of 10−29 e ⋅ cm by using polarized “magic” momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the standard model at the scale of 3000 TeV.

43 PARTICLE ACCELERATORS↗

How to Reach a Thousand-Second in-Plane Polarization Lifetime with 0.97 - GeV / c Deuterons in a Storage Ring

Here, we observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of a magnetic storage ring (COSY). This long spin coherence time is maintained through a combination of beam bunching, electron cooling, sextupole field corrections, and the suppression of collective effects through beam current limits. This record lifetime is required for a storage ring search for an intrinsic electric dipole moment on the deuteron at a statistical sensitivity level approaching 10 -29 $e$ cm.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Untangling the contributions of image charge and laser profile for optimal photoemission of high-brightness electron beams

Using our model for the simulation of photoemission of high brightness electron beams, we investigate the virtual cathode physics and the limits to spatio-temporal and spectroscopic resolution originating from the image charge on the surface and from the profile of the exciting laser pulse. By contrasting the effect of varying surface properties (leading to expanding or pinned image charge), laser profiles (Gaussian, uniform, and elliptical), and aspect ratios (pancake- and cigar-like) under different extraction field strengths and numbers of generated electrons, we quantify the effect of these experimental parameters on macroscopic pulse properties such as emittance, brightness (4D and 6D), coherence length, and energy spread. Based on our results, we outline optimal conditions of pulse generation for ultrafast electron microscope systems that take into account constraints on the number of generated electrons and on the required time resolution.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Space Charge Simulation in COSY using The Fast Multipole Method

A method is implemented in COSY Infinity that allows the computation of space charge effects of arbitrary and large distributions of particles in an efficient and accurate way based on a variant of the Fast Multipole Method (FMM). It relies on an automatic multigrid-based decomposition of charges in near and far regions and the use of high-order differential algebra methods to obtain decompositions of far fields that lead to an error that scales with a high power of the order. Given an ensemble of N particles, the method allows the computation of the self-fields of all particles on each other with a computational expense that scales as O(N). Further- more, the method allows the computation of all high-order multipoles of the space charge fields that are necessary for the computation of high-order transfer maps and all resulting aberrations. Space charge effects are crucial in modeling the latter stages of the six-dimensional (6D) cooling channel for the Muon Collider. Results of simulating the 6D cooling channel for the Muon Collider using the FMM method and other tools and improvements implemented for ionization cooling lattices are presented.

Loseth, B.↗