Hadronteraphy is a cancer treatment method utilizing beams of charged particles heavier than electrons, such as protons or carbon ions, to target and eliminate tumors while minimizing damage to surrounding healthy tissues. The treatment beams are generated by means of particle accelerators, such as synchrotrons, which deliver particles with the desired energy directly to the patient via the gantry. The motion of the accelerated beam is guided and focused by superconductive magnets that provide high magnetic fields necessary for particle motion in accelerators. Higher magnetic fields allow for more compact accelerators. These magnets use coils made of superconductive material, which eliminates electrical resistance and expels magnetic fields from the material. The gantry, a cylindrical scanner assembly used in medical 3D imaging or treatment, rotates around the patient and houses the radiation detectors and sometimes the radiation source. The aim of the thesis is to estimate the energy deposition in the superconducting magnets of the Carbon-ions gantry for CNAO, being design in the context of the HITRIplus and SIG projects. The extracted beam can deviate from its planned trajectory, impinging on the magnet and interacting with it. This can happen during machine commissioning or in dedicated session of machine development. The relevant topic is the potential overheating of superconducting magnets, which can trigger quench events in the device. It leads to the loss of superconductivity: when this happens, the circulating current is quickly dissipated and the magnet do not function anymore. The recovery can be lengthy and impacting the treatment schedule. The thesis focuses on the energy deposition mechanisms induced by the interaction between the accelerated particle beam and the coils within the gantry: the energy deposited by the radiation-matter interaction can lead to local quenching events. This thesis examines the energy deposition of hadrons by means of Monte Carlo simulations using the FLUKA code. The conducted studies consider the design of The SIG demonstrator as superconducting dipole magnet. A sensitivity analysis is conducted to identify key parameters, such as the spot size of the Gaussian particle beam impinging on magnet or the impact angle or the materials selected for the study, and factors such as the type of hadron and their energy. Lastly, correlations and trends are identified, elucidating the relationship between energy deposition and various parameters describing the optical characteristics of the beam.
La adroterapia è un metodo di trattamento del cancro che utilizza fasci di particelle cariche più pesanti degli elettroni, come protoni o ioni carbonio, per colpire ed eliminare i tumori, minimizzando i danni ai tessuti sani circostanti. I fasci di trattamento sono generati mediante acceleratori di particelle, come i sincrotroni, che forniscono particelle con l'energia desiderata direttamente al paziente tramite il gantry. Il movimento del fascio accelerato è guidato e focalizzato da magneti superconduttivi che forniscono campi magnetici elevati necessari per il movimento delle particelle negli acceleratori. Campi magnetici più elevati permettono di costruire acceleratori più compatti. Questi magneti utilizzano bobine realizzate con materiale superconduttore, che elimina la resistenza elettrica ed espelle i campi magnetici dal materiale. Il gantry, un assemblaggio cilindrico utilizzato per la scansione 3D medica o per il trattamento, ruota intorno al paziente e contiene i rilevatori di radiazioni e talvolta anche la sorgente di radiazioni. Lo scopo della tesi è stimare la deposizione di energia nei magneti superconduttivi del gantry per ioni carbonio del CNAO, progettato nel contesto dei progetti HITRIplus e SIG. Il fascio estratto può deviare dalla sua traiettoria pianificata, colpendo il magnete e interagendo con esso. Questo può accadere durante la messa a punto della macchina o in sessioni dedicate allo sviluppo della macchina. Un argomento rilevante è il potenziale surriscaldamento dei magneti superconduttivi, che può innescare eventi di quench nel dispositivo. Questo porta alla perdita della superconduttività: quando ciò accade, la corrente circolante viene rapidamente dissipata e il magnete cessa di funzionare. Il recupero può essere lungo e influire sul programma di trattamento. La tesi si concentra sui meccanismi di deposizione di energia indotti dall'interazione tra il fascio di particelle accelerato e le bobine all'interno del gantry: l'energia depositata dall'interazione radiazione-materia può portare a eventi di quench locali. Questa tesi esamina la deposizione di energia degli adroni mediante simulazioni Monte Carlo utilizzando il codice FLUKA. Gli studi condotti considerano la progettazione del dimostratore SIG come magnete dipolare superconduttivo. Viene condotta un'analisi di sensibilità per identificare i parametri chiave, come la dimensione dello spot del fascio di particelle gaussiane che colpisce il magnete, l'angolo di impatto, i materiali selezionati per lo studio, il tipo di adrone e la loro energia. Infine, vengono identificate correlazioni e tendenze, chiarendo la relazione tra la deposizione di energia e vari parametri che descrivono le caratteristiche ottiche del fascio.
Energy deposition studies in a superconducting dipole magnet for the CNAO C-ion gantry
Tosetti, Giulia
2023/2024
Abstract
Hadronteraphy is a cancer treatment method utilizing beams of charged particles heavier than electrons, such as protons or carbon ions, to target and eliminate tumors while minimizing damage to surrounding healthy tissues. The treatment beams are generated by means of particle accelerators, such as synchrotrons, which deliver particles with the desired energy directly to the patient via the gantry. The motion of the accelerated beam is guided and focused by superconductive magnets that provide high magnetic fields necessary for particle motion in accelerators. Higher magnetic fields allow for more compact accelerators. These magnets use coils made of superconductive material, which eliminates electrical resistance and expels magnetic fields from the material. The gantry, a cylindrical scanner assembly used in medical 3D imaging or treatment, rotates around the patient and houses the radiation detectors and sometimes the radiation source. The aim of the thesis is to estimate the energy deposition in the superconducting magnets of the Carbon-ions gantry for CNAO, being design in the context of the HITRIplus and SIG projects. The extracted beam can deviate from its planned trajectory, impinging on the magnet and interacting with it. This can happen during machine commissioning or in dedicated session of machine development. The relevant topic is the potential overheating of superconducting magnets, which can trigger quench events in the device. It leads to the loss of superconductivity: when this happens, the circulating current is quickly dissipated and the magnet do not function anymore. The recovery can be lengthy and impacting the treatment schedule. The thesis focuses on the energy deposition mechanisms induced by the interaction between the accelerated particle beam and the coils within the gantry: the energy deposited by the radiation-matter interaction can lead to local quenching events. This thesis examines the energy deposition of hadrons by means of Monte Carlo simulations using the FLUKA code. The conducted studies consider the design of The SIG demonstrator as superconducting dipole magnet. A sensitivity analysis is conducted to identify key parameters, such as the spot size of the Gaussian particle beam impinging on magnet or the impact angle or the materials selected for the study, and factors such as the type of hadron and their energy. Lastly, correlations and trends are identified, elucidating the relationship between energy deposition and various parameters describing the optical characteristics of the beam.File | Dimensione | Formato | |
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2024_07_Tosetti_Thesis.pdf
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2024_07_Tosetti_ExecutiveSummary.pdf
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https://hdl.handle.net/10589/223379