Particle Tracking With Space Charge Effects Using Graphics Processing Unit

Particle tracking simulations with space charge effects are very important for high-intensity proton rings. Since they include not only Hamiltonian mechanics of a single particle but also constructing charge densities and solving Poisson equations to obtain the electromagnetic field due to the space charge, they are extremely time-consuming. We have newly developed a particle tracking simulation code that can be used in graphics processing units (GPUs). GPUs have strong capacities of parallel processing so that the calculation of single-particle mechanics can be done very fast by complete parallelization. Our new code also includes the space charge effect. It must construct charge densities, which cannot be completely parallelized. For the charge density construction, we can use “shared memory,” which can be accessed very fast from each thread. The usage of shared memory is another advantage of GPU computing. As a result of our new development, we increase the speed of our particle tracking, including the space charge effect approximately ten times faster than that in the case of our conventional code used in CPU.