CSIC / IFIC – Instituto de Fisica Corpuscular (CSIC-UV)

Application of high gradient RF technology for hadron therapy accelerators

Trainee: Anna Vnuchenko
Supervisor: Juan Fuster Verdu

A new S-band High-Gradient (HG) RF lab is being constructed at IFIC, under a FEDER funded collaboration agreement between the University of Valencia and the Spanish General Administration (MINECO) for the building integration and the equipment of scientific instrumentation. The main objective of the laboratory is the study of vacuum breakdown phenomenology of 3 GHz HG accelerating structures and development of normal-conducting RF technology, in particular for medical applications.

The current activities of the IFIC HG-RF laboratory are developed in collaboration with CERN RF CLIC group within the framework of the knowledge transfer project ‘High-power testing of a medical highgradient accelerating structure for proton therapy’, for the design and testing of novel HG structures for compact and efficient proton beam facilities for cancer therapy.

The Fellow has contributed to testing and conditioning process, including breakdown studies of two novel high-power prototype 3 GHz accelerating structures commonly used in proton linacs. These accelerating structures are being designed and built at CERN to prove the principle of HG acceleration of low energy protons required for hadron therapy. The Fellow participated in the operation of the CERN X- and S-band testing facilities (Xboxes and Sbox). The first high gradient structure prototype for a medical proton linac has been tested using the high-power infrastructure from the CLIC experimental program. The Fellow has actively participated in testing and data analysis which has been used to improve the understanding of the physics of the breakdown phenomena and the limit in highgradient performances of normal conducting
acceleration structures. The experience acquired in the running of the Xboxes will be used to contribute to the finalization of the implementation of the HG-RF lab constructed in IFIC. The test of the second proton linac structures at University of Valencia will complement this work.

The Fellow participated in studies of other low energy ion accelerators to be used as injector for hadron therapy linacs. Development of a compact and low-cost RFQ allows adapting the previous TERA design to modern technologies and building on the experience from the construction of CERN’s Linac 4 RFQ.

Image courtesy of CSIC/IFIC