Impact of Bayesian weighting in a probabilistic nowcasting from INCA and C-LAEF

Presentación realizada en la 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019

Development of the orbit correction procedure and simulations on rf-noise driven slow resonant extraction of MedAustron synchrotron

MedAustron is a synchrotron-based hadron therapy and research center in Austria currently in the commissioning phase. The accelerator is capable of delivering protons up to an energy of 60 - 800 MeV and carbon ions to 120 - 400 MeV per nucleon. This thesis consists of two parts focusing on two distinct topics of beam optics and beam dynamics. The aim of the first topic was to study the orbit correction procedure of the synchrotron. Commonly dedicated programs like MAD-X perform this computation and the results can be applied directly. However, first tests showed that this program cannot be used in the case of the off-momentum operated MedAustron synchrotron. Therefore a procedure pre-processing the input data in a way that standard orbit correction algorithms implemented in MAD-X can be used was developed. This procedure then was validated and verified successfully. The second topic of this thesis focuses on an alternative slow third order extraction driving mechanism using longitudinal RF-noise. For this purpose a dedicated single particle tracking code as well as analysis tools were programmed. In this study the extraction method using one frequency band only was used to investigate the feasibility of the method and to find appropriate settings and parameters. However, the results show that, within the investigated parameter range no setup could be found delivering the smooth extraction flux required for medical therapy. Results of this study have been presented at the 4th International Particle Accelerator Conference in May 2013.7

Tomography of Horizontal Phase Space Distribution of a Slow Extracted Proton Beam in the MedAustron High Energy Beam Transfer Line

MedAustron is a synchrotron based hadron therapy and research center in Wiener Neustadt, Austria, which currently is under commissioning for the first patient treatment. The High Energy Beam Transfer Line (HEBT) consists of mul- tiple functional modules amongst which the phase-shifter- stepper PSS is the most important module located where the dispersion from the synchrotron is zero and upstream of the switching magnet to the first irradiation room. The PSS is used to control the beam size for the downstream modules and for this scope rotates the beam in horizontal phase space by adjusting the phase advance. This functionality is used in this study to measure beam profiles for multiple phase space angles which act as input for a tomographic reconstruction. Simulation and measurement results are presented

Overview and Status of the MedAustron Ion Therapy Center Accelerator

The synchrotron-based MedAustron accelerator in Wiener Neustadt, Austria, has seen the first clinical beam and has been certified as a medical accelerator in December 2016. This represented a major milestone for the facility whose original design originated more than a decade ago and construction started four years ago. The accelerator is designed to deliver clinical proton beams 60-253 MeV and carbon ions 120-400 MeV/u to three ion therapy irradiation rooms (IRs), including a room with a proton Gantry. Beams up to 800 MeV will be provided to a fourth room dedicated to non-clinical research. Presently, proton beams are delivered to the horizontal beam lines of three irradiation rooms. In parallel, commissioning of the accelerator with Carbon ions and the installation of the Gantry beam line are ongoing. At MedAustron, a third-order resonance extraction method is used to extract particles from the synchrotron in a slow controlled process over a spill time of 0.1-10 seconds to facilitate the measurement and control of the delivered radiation dose during clinical treatments. The main characteristics of the accelerator and the results obtained during the commissioning are presented

The Beam Quality Assurance of the MedAustron Particle Therapy Accelerator

The delivery of clinical beams for patient treatment at the MedAustron Ion Therapy Center requires extensive accelerator performance verifications, which are performed in several steps. In first instance, the key parameters of the beam delivered to the irradiation rooms (beam position, spot size, energy and intensity) are verified via measurements performed with beam diagnostic devices distributed along the accelerator. The second verification step consists in testing the full functionality of the therapy accelerator, including the medical frontend: scanning magnets performance, intensity monitoring and safety features. The final verification step is the quality assurance (QA) done by the medical department. An extended set of reference measurements assures the fast identification of the faulty components in case of a performance deviation, and the totality of the accumulated data allows in-depth analysis of the accelerator performance. We present here the trends and correlations observed during the first verification step for the most important parameters, as well as the lessons learned through all the implementation stages of the beam quality assurance

Beam Measurements in the MedAustron Synchrotron With Slow Extraction and Off-Momentum Operation

The MedAustron Ion Therapy Center is a medical accelerator facility for hadron therapy cancer treatment using protons and carbon ions. The facility features 4 irradiation rooms, three of which are dedicated to clinical operation and a fourth one dedicated to non-clinical research. The latter was handed over to researchers in autumn 2016. A 7 MeV/n injector feeds a 77 m circumference synchrotron which provides beams for treatment and research. Routine verification measurements in the synchrotron involve beam emittance, dispersion as well as tunes and chromaticity. The horizontal and vertical emittance are measured using scraping plates and a direct current transformer. The dispersion function in the ring is determined by sweeping the synchrotron RF frequency while measuring the beam position in the shoe-box pick-ups. The horizontal and vertical betatron tune and chromaticity are measured with Direct Diode Detection electronics, developed at CERN, while changing the beam position with the RF radial loop. The beam is kept off-momentum, thus in dispersive regions the closed orbit is largely offset from the central orbit. Methods for beam measurements in the synchrotron are presented

A seamless probabilistic forecasting system for decision making in Civil Protection

An innovative seamless probabilistic forecasting system has been developed within the EU project PROFORCE (Bridging of PRObabilistic FORecasts and Civil protEction). The system merges four different ensemble prediction systems and provides weather forecasts and the corresponding forecast uncertainties in a seamless way from several days ahead to the nowcasting range with increasing time and space resolution. The probabilistic information from the seamless system is tailored to the needs of the end users in civil protection and is illustrated on a user-friendly web portal. The seamless weather forecasting and warning system is impact based and was designed by meteorologists and civil protection users together. This article describes the seamless system and discusses its perception in civil protection based on several severe weather situations occurring during the two years of the project. It has been demonstrated that the seamless forecasts allow a longer preparation time due to earlier warnings. The probability information can help in planning and decision making in civil protection. The weaknesses of the forecasting system, in particular the limits in predicting small scale convective systems, are also discussed in the paper