T. Matlocha on Ion Source Test Stand Optimization in PSI

On Tuesday, September 17, 2019, another of the seminars of KINEÓ participants took place in the NPI meeting room. Ing. Tomáš Matlocha from the Department of Accelerators of the NPI introduced – after his return from a six-month internship at the PSI research institute in Villigen, Switzerland – optimization of the test stand parameters of the medical cyclotron ion source. Internship was supported by the KINEÓ project.

The COMET medical proton cyclotron for a maximum energy of 250 MeV is part of the PSI proton therapy program. One of the key components of this accelerator is the Penning-type internal ion source whose operating parameters are optimized in a test stand simulating conditions in the central region of the cyclotron.

During his internship, T. Matlocha, using specialized software CST Particle Studio, conducted analyzes of test stand efficiency and its ability to operate in a wide range of magnetic fields. Based on this analysis, he proposed adjusting the internal configuration of the test stand to increase both magnetic field and extraction voltage ranges. For the COMET cyclotron, the possibility of using an external ion beam introduced into the acceleration area through the axial channel was investigated using a spiral inflector.

During the return phase T. Matlocha worked on increasing the extraction efficiency of the U-120M cyclotron in Řež, especially on the preparation of electromagnetic fields and CAD models of the cyclotron and their implementation into simulation software. He applied the know-how, acquired during his Swiss internship, to the procedures for creating cyclotron models and simulating their properties, which greatly increased work efficiency. For the OPAL software package, T. Matlocha created maps of the electric and magnetic fields of the U-120M cyclotron and simulated the basic parameters of one of his proton modes at 28 MeV. The OPAL tool, designed to calculate the inter-action of acceleration and transport structures with charged particles, may also be useful for the planned modernization of the U-120M isochronous cyclotron in Řež and associated ion-optical beam lines.