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Improved emittance measurement in accelerator systems — Over €360,000 of funding through the LOEWE initiative

Photo: C. Pomplun, GSI

ROSE prototyp



Developed by two GSI researchers, the ROSE system (ROtating Scanner for 4-dimensional Emittance measurement) will receive funding of more than €360,000 from the LOEWE funding initiative of the State of Hesse for a period of three years from May 2019 on. The purpose of the current project is the development and system integration of a software package for ROSE. The applicant is NTG (New Technologies GmbH of Gelnhausen), a company cooperating with GSI, though the greater part of the funding, approx. €200,000, will go to GSI for personnel costs.

ROSE is a novel system for measuring four-dimensional (4D) transversal ion beam emittance. This is the volume occupied by an ion beam in the transversal phase space. Knowledge and manipulation of the ion beam emittance in the accelerator are relevant for improving the beam quality. Previously, only the horizontal and vertical projections of the 4D phase space could be measured for heavy ion beams with energies above 100 kilo-electron volts per nucleon. These measurements lack information on the coupling of the planes, since they represent only a shadow image of the actual volume in the phase space. Researchers Dr. Michael Maier and Dr. Chen Xiao of GSI's accelerator division developed the rotatable emittance measurement system ROSE at GSI to overcome this limitation. As a result, operators of heavy-ion accelerator systems will now have a universal measuring tool available to them for the first time that will enable measurement of the couplings between the planes. This allows a considerably more efficient tuning of the accelerator systems.

Maier describes his invention as follows: “In addition to the capability of a complete 4D measurement of the transversal beam emittance, the rotatability of the system allows one measurement plane to be spared, since all spatial directions can be approached from a single device. Since the rotary drive is significantly cheaper than the electronics required for a complete extra measurement plane, this reduces the costs of the emittance measurement system.”

The software package to be developed in the funded project and integrated into the overall ROSE system is intended to combine the four necessary and hitherto separate sub-functions of planning, controling, measuring and evaluating the 4D emittance measurement for the first time. In the project, this software and the previously developed components, the ROSE detector and the ‘Robomat’ electronic control system (previously also funded by the WIPANO project of the German Ministry of Economic Affairs and Energy), will be brought together to form a prototype of the complete 4D ROSE emittance system. Outside the project, the prototype will be tested at GSI in routine operation, optimized jointly with NTG, and finally marketed by NTG as a complete system. The prototype used in routine operation at GSI will also serve as a demonstrator for NTG.

“For users, the clear advantages are a shorter measurement time, less dependence on highly qualified personnel for planning and carrying out the measurement, the possibility of directly correcting the beam at a later stage and the possible minimization of installation and operating costs for the accelerator system,” explains Martina Bauer, who oversees the ROSE project as part of the GSI technology transfer, describing the benefits of the new technology. “Both in functional and economic terms, ROSE is superior to the greater part of the 2D emitter measuring systems currently available. ROSE may generally replace these when they are updated, or may be used directly in new accelerator systems. In Germany at least ten research institutes and a number of companies are now working with systems compatible with ROSE. According to the cooperation partner NTG there are more than 100 interested institutions across Europe in the fields mentioned above, while in particular the Asian market offers a far greater potential.”

Forecasts anticipate a global market share of approximately 20% and a significant increase in sales of 250% in the field of beam diagnostics, with a correspondingly significant positive effect on the employment of dedicated personnel by NTG. In addition, ROSE emittance measurements will enable many new research projects in the field of accelerator physics to be carried out. Especially with regard to the large-scale FAIR (Facility for Antiproton and Ion Research) project and the scientific experiments planned in relation to it, the technical possibilities now opened up by ROSE are a key element for meeting the requirements of the new and world-wide unique accelerator facility currently under construction at GSI in Darmstadt.(cp)

ROSE prototyp
Dr. Tobias Engert (r.) and Dr. Alicja Surowiec from Technology Transfer inspect the ROSE prototype at the UNILAC accelerator of GSI. It is a development of Dr. Michael Maier (l.) und Dr. Chen Xiao (2nd from left) used to improve the measurement of the ion beam emittance.
Photo: C. Pomplun, GSI