Meaningful prediction and enhancement of spin-polarization in the RHIC/EIC accelerator complex relies on accurate modeling of each sub-component. Here we describe a symplectic field approximations of both Siberian Snakes in the AGS, enabling practical long-term tracking calculations. Without such symplectic representations, particle motion destabilizes very quickly close to injection energy. This optical instability manifests in $O(10^3)$ turns, and makes dynamic aperture smaller than realistic emittances. Combined with optimization using the Bmad toolkit, we implement steering and optical corrections of the snake effects at 80 distinct energies from injection to extraction, mimicking the measured lattice conditions at each energy. This process unveils unforeseen snake distortions of the vertical dispersion near injection energy, which are addressed. By interpolating between such optimized lattice configurations, Bmad's tracking capabilities allow advanced simulation of polarization transmission through the full AGS cycle.

Meaningful prediction and enhancement of spin-polarization in the RHIC/EIC accelerator complex relies on accurate modeling of each sub-component. Here we describe a symplectic field approximations of both Siberian Snakes in the AGS, enabling practical long-term tracking calculations. Without such symplectic representations, particle motion destabilizes very quickly close to injection energy. This optical instability manifests in $O(10^3)$ turns, and makes dynamic aperture smaller than realistic emittances. Combined with optimization using the Bmad toolkit, we implement steering and optical corrections of the snake effects at 80 distinct energies from injection to extraction, mimicking the measured lattice conditions at each energy. This process unveils unforeseen snake distortions of the vertical dispersion near injection energy, which are addressed. By interpolating between such optimized lattice configurations, Bmad's tracking capabilities allow advanced simulation of polarization transmission through the full AGS cycle.

One of the challenges of designing the Electron-Ion Collider (EIC) is to mitigate beam-induced heating due to the intense electron and hadron beams. Heating of the Electron Storage Ring (ESR) vacuum chamber components is mainly due to beam-induced resistive wall loss and synchrotron radiation. For the Hadron Storage Ring (HSR) components, heating is mainly due to resistive wall loss because of the large radial offset, electron cloud formation, and heat conduction from room temperature to cryo-components. In this paper, we provide an update on the beam-induced heating and thermal analysis for some EIC vacuum chamber components including the RF-fingers module of HSR cryogenic interconnect assembly. In addition, we provide simulation update for the HSR snake BPM, and abort kicker along with the change in ESR vacuum chamber profile. Similar analysis for other HSR and ESR components are available in Ref.~\cite{sangroulalocalized_NAPAC22, sangroula2023beam}. Our approach for thermal analysis involves calculating resistive wall losses using CST, evaluating heat loss due to synchrotron radiation and electron cloud formation and incorporating these losses into ANSYS for finding the temperature distribution.

The Electron-Ion Collider (EIC) utilizes the existing Relativistic Heavy Ion Collider (RHIC) rings as a Hadron Storage Ring (HSR) with some modifications. However, this presents significant challenges, primarily due to beam-induced Resistive Wall (RW) heating resulting from a larger radial offset and shorter EIC bunches (up to 10 times shorter than RHIC). Additionally, the formation of an electron cloud further complicates matters. To address these issues and operate the HSR effectively, this paper focuses on the RW heating and thermal analysis of the EIC HSR beam screen. Our approach involves the insertion of a copper-coated stainless steel beam screen with cooling channels and longitudinal slots. We conducted a detailed thermal analysis, assessing piecewise RW losses around the beam screen's profile due to an offset beam, employing the 3D commercial code CST. These losses, along with realistic boundary conditions, were then integrated into another code, ANSYS, to determine the thermal distribution.

Studying the energy deposition in accelerator components, mechanical supports, services, ancillary equipment and shielding requires a detailed computer readable description of the component geometry. The creation of geometries is a significant bottleneck in producing complete simulation models and reducing the effort required will allow non-experts to simulate the effects of beam losses on realistic accelerators. This paper describes a flexible and easy to use Python package to create geometries usable by either Geant4 (and so BDSIM or G4Beamline) or FLUKA either from scratch or by conversion from common engineering formats, such as STEP or IGES created by industry standard CAD/CAM packages. This paper describes the updates to pyg4ometry since IPAC19. These updates include ROOT geometry loading, refactored geometry processing using CGAL, direct CAD file loading using OpenCASCADE, geometrical feature extraction and geometry comparison algorithms. The paper includes small examples of the new features with explanations.

The peak-detected Schottky system is a powerful diagnostic tool for observing the longitudinal beam parameters. According to the theoretical model, the peak value of the signal from a wide-band pick-up contains information on particle distribution as a function of the synchrotron frequency. Due to intrinsic assumptions needed for modelling the acquisition set-up and uncertainties in beam parameters, a one-to-one comparison of predictions and measurements remains a challenge. We obtained, for the first time, the peak-detected Schottky spectra in macro-particle simulations for a simplified experimental set-up. Following refinement of the theoretical model, a direct comparison was performed under controlled conditions. Agreement with the numerical results was improved by introducing an additional form factor describing the probability of a particle being present in the observation window. Modifications due to collective effects are briefly discussed as well.

Multipacting is a phenomenon arising from the emission and subsequent multiplication of charged particles in accelerating radiofrequency (RF) cavities, which can limit the achievable RF power. Predicting field levels at which multipacting occurs is crucial for optimizing cavity geometries. This paper presents a new open-source Python code for analyzing multipacting in 2D axisymmetric cavity structures. The code leverages the NGSolve framework to solve the Maxwell Eigenvalue Problem (MEVP) to obtain the cavity's resonant modes' electromagnetic fields. The relativistic Lorentz force equation governing the motion of charged particles is then integrated using the fields within the cavity. Benchmarking against existing multipacting analysis tools is performed to validate the code's accuracy and efficiency. The open-source nature of the code fosters further development and customization for specific applications.

SLAC has developed the parallel finite element electromagnetics simulation suite ACE3P which employs the parallel high-order finite element (FE) method to solve Maxwell's equations at the macroscopic level. Under the support of an SLAC LDRD, optical nonlinearities in the transient regime have been incorporated into the ACE3P time-domain solver for the investigation of nonlinear physical processes such as harmonic generation, parametric processes and electro-optic effects. This nonlinearity will be applied to provide high fidelity modeling capability to quantum frequency converters employing nonlinear materials in quantum information science applications. The new solver has been benchmarked against the commercial solver ANSYS Lumerical. Furthermore, we have completed the first prototype of the new nonlinear solver employing PETSc, a powerful suite of data-structure-neutral scalable numerical routines for large-scale linear and nonlinear problems. The PETSc library and the Scalable Nonlinear Equations Solvers (SNES) components include backend CPU/GPU implementations thus offering the needed numerical methods for solving Maxwell’s equations with nonlinearities.

This work aims to improve the ability of particle accelerator researchers to develop high-performance accelerator cavity designs by creating an overall multiphysics framework that integrates and couples existing application codes. This framework will allow accelerator researchers to build multiphysics models that will optimize cavity design, improve understanding of whole-device performance, and reduce the development and fabrication costs of accelerator research. We utilize the open-source VizSchema data standard as an intermediate data structure interface layer to standardize interfaces between individual application codes. VizScema is extensively documented online, and plugins for VizSchema are available for popular visualization packages, including VisIt and ParaView. Currently, the work focuses on coupling the EM field solver COMSOL and the electron gun code MICHELLE to allow COMSOL field-solve results to be seamlessly used by MICHELLE for particle-solve. Later work will extend this integration to include other fields, particles, and thermodynamics simulation codes.

We present a high-performance solver for the magnetostatic equations. The solver can simulate nonlinear and anisotropic magnetic materials on a highly variable grid, enabling efficient resolution of fine features even in very large systems. It is built on the Tpetra parallel sparse linear algebra package, allowing it to handle problems with billions of degrees of freedom and employ hardware acceleration with Nvidia graphics processing units. Integration into the VSim electromagnetics software allows users to design magnetic systems using existing graphical interface features. Example simulations of nonlinear magnets, with application to particle accelerator magnet design, will be shown.

SLAC developed ACE3P is a parallel multi-physics electromagnetics (EM) simulation toolkit aiming for virtual prototyping of accelerator and RF component design, optimization and analysis. In this paper, we will present the latest progress on ACE3P modeling capabilities. First, for the time domain solver T3P, modeling of nonlinear materials with higher-order electric susceptibilities has been developed. It can be used to design the devices for THz accelerators and quantum information science. Second, for the particle tracking module Track3P, external DC fields calculated by the electrostatic solver embedded in the DC gun module Gun3P can be read in to model the use of DC bias in mitigating multipacting in accelerator structures. Third, a surface impedance boundary condition to treat a thin layer of lossy materials has been implemented in the frequency domain S-parameter module S3P. This enables calculation without explicitly building an extremely fine mesh in the layer and substantially reduces the computational cost when a much larger mesh would have been needed to resolve the field in the layer. Fourth, a code integration effort has been embarked to integrate Track3P with the radiation transport code Geant4 for modeling radiation effects for dark current in accelerator structures. The applications using these new model capabilities will be presented in the paper as well.