MedAustron is an ion therapy facility located in Wiener Neustadt, Austria, which uses third order resonant slow extraction to deliver protons and carbon ions for clinical irradiation. The foreseen upgrade of the new low level RF (LLRF) system facilitates advanced longitudinal beam manipulation schemes involving multiple RF harmonics, which will be exploited to improve the slow extraction process and the consequent spill characteristics. To support these studies and provide a new diagnostic tool longitudinal tomography is being implemented. This proceeding presents the employed measurement set-ups and compares the first obtained tomographic reconstructions with BLonD simulations.

MedAustron is a state-of-the-art synchrotron-based accelerator complex that provides irradiation with proton and carbon ion beams. The implemented DCCT feedback based control of the current provides good results for magnets of the accelerator in terms of precision and accuracy. However, since the B-Field of the main ring dipoles is not directly controlled, parasitic, time consuming effects cannot be compensated. Hence, the implementation of a B-Field control system offers a major improvement opportunity for the operation. This contribution presents the measurement chain of the proposed solution which is centered around a Hall probe located in the so-called B-train magnet. This approach requires an assessment of the applicability of local Hall probe measurements for this purpose, including the development of a model for relating the respective local measurement to the integral field. Ultimately, the Hall probe has shown characteristics of high accuracy and a measurement uncertainty that is below the overall field error target of 2 units. The model was tested under laboratory conditions and an accurate estimation of the integral field has been observed in the scope of simulations.

The temporal characteristics of ultra-high dose rate beams delivered for FLASH research are often dictated by machine constraints, making it challenging to compare the outcomes across studies performed at different facilities. To broaden the opportunities for systematic, non-clinical FLASH research, this study explores methods to deliver beams with customizable time structures from a medical synchrotron. The studies are being performed at the center for ion beam therapy and research MedAustron and aim at extracting ultra-high dose rate proton beams in a series of pulses with adjustable dose per pulse, pulse length and pulse separation down to sub-ms levels. This contribution describes the implementation of the extraction methods explored for this application, phase displacement and radio frequency knockout extraction, and presents first measurement results. The measurement setup employs a silicon carbide detector in conjunction with a 20 MHz bandwidth amplifier, enabling intensity measurements with a resolution exceeding the synchrotron revolution period.

With a very low relative charge-to-mass ratio offset of approximately 0.065%, helium (⁴He²⁺) and carbon ions (¹²C⁶⁺) are interesting candidates for being simultaneously accelerated in hadron therapy accelerators. At the same energy per nucleon, helium ions exhibit a stopping range approximately three times greater than that of carbon ions. They can therefore be exploited for online range verification in a detector downstream of the patient during carbon ion therapy. The synchrotron-based MedAustron Ion Therapy Center provides the opportunity to study the feasibility of such a mixed beam-based in-vivo range verification system due to the availability of 120-402.8 MeV/u carbon beams and the ongoing commissioning of 39.8-402.8 MeV/u helium beams. One possibility for creating this mixed beam is accelerating ⁴He²⁺ and ¹²C⁶⁺ sequentially through the LINAC and subsequently “mixing” the ion species at injection energy in the synchrotron with a double injection scheme. This contribution introduces this newly proposed injection scheme, outlines challenges and presents first feasibility estimates obtained through measurements and particle tracking simulations.

In recent years, mixed helium and carbon ion irradiation schemes have been proposed to facilitate in-vivo range verification in ion beam therapy. Such a scheme proposes to deliver both ion species simultaneously, with the idea of performing the treatment with carbon ions, while exploiting helium for online dosimetry downstream of the patient. The center for ion beam therapy and research MedAustron supplies protons and carbon ions for clinical treatment. It is currently being commissioned to additionally provide helium ions for non-clinical research, opening the opportunity for exploring the feasibility of mixed beam irradiation. A key aspect in this context is the slow extraction of the ion mix, which is affected by the relative charge-to-mass ratio offset between the two ions of approximately 6e-4. This contribution analyses differences in the transverse phase space and tune distributions of the two ion species and subsequently discusses first simulation results of the extraction process.