Scientific Highlights from the Department "Large Research Facilities" (GFA)

Scientific Highlights

Best publication

30.09.2017 A team of GFA and CPT physicists has worked out a novel achromatic beam optics concept for a proton therapy gantry. The article on the concept in the journal Zeitschrift für Medizinische Physik has been awarded a prize for the best publication in 2016. The jury states: „The paper of Alexander Gerbershagen et al. entitled „A novel beam optics concept in a particle therapy gantry utilizing the advantages of superconducting magnets” describes a new concept of a first order design of the beam optics of a superconducting proton therapy gantry beam. The jury was impressed by the well-structured experimental work with clear improvement of large momentum acceptance in the gantry which opens the possibility of implementation new and faster dose application techniques in proton therapy.”
The announcement and a link to the paper can be found here:
The prize was awarded to Dr. Gerbershagen at the yearly assembly of the German Society for Medical Physics in Dresden, September 2017.

X-band prototype structure

08.11.2016 Radio-frequency structures at X-band frequencies (~ 12 GHZ) are being considered for applications in compact Free Electron Lasers, medical linacs, a future linear collider (CLIC project) and as a diagnostic for measuring ultra-short (femtosecond) electron pulses in FELs. A first prototype of such a structure has been built at PSI employing the realization procedures that have been developed for the C-Band (6 GHz) structures of the SwissFEL linac. The structure was designed in the framework of a collaboration between CERN and the Large Research Facilities Division (GFA) of PSI with the financial support of the SNF (grant 20FL20_147463). The individual cells were precision machined by the company “VDL Enabling Technologies Group Switzerland AG” and the structure brazed by the mechanical engineering department (AMI) at PSI. In the near future, it will be tested at high power on a test bench at CERN.

First acceleration with the SwissFEL C-band module

13.09.2016 On Thursday 08/09/2016, the first C-band module boosted an electron beam from 150MeV to 390 MeV. This is the first beam acceleration test of a C-band module in PSI and is an important milestone for the project, since the main accelerator consists of 26 C-band modules of the same kind. In the module, the RF pulse is first generated by a pulsed modulator- klystron amplifier, placed in the technical gallery, and is guided to the pulse compressor (BOC), where it is compressed by a factor four and split to the four accelerating cavities in the beam tunnel. The 104 accelerating cavities are two meters long and have been developed at PSI, produced together with the VDL Enabling Technologies Group Switzerland AG. The 26 BOCs have been developed and fully produced at PSI. An outstanding feature of the SwissFEL C-band module is that for the first time, accelerating structures and pulse compressors have been produced on frequency, i.e. without any tuning of the frequency. During the acceleration test, the module was operating at the nominal RF power setting of 36 MW and 3 microseconds pulse at 5.712GHz and a repetition rate of 10Hz. The measured beam energy gain was 240 MeV, with excellent agreement with the expected value of 233 MeV. The installation of the C-band modules has been completed with the mounting of the last unit on Tuesday 13/09/2016.