Evolution of a beam dynamics model for the transport lines in a proton therapy facility

Despite the fact that the first-order beam dynamics models allow an approximated evaluation of the beam properties, their contribution is essential during the conceptual design of an accelerator or beamline. However, during the commissioning some of their limitations appear in the comparison against measurements. The extension of the linear model to higher order effects is, therefore, demanded. In this paper, the effects of particle-matter interaction have been included in the model of the transport lines in the proton therapy facility at the Paul Scherrer Institut (PSI) in Switzerland. To improve the performance of the facility, a more precise model was required and has been developed with the multi-particle open source beam dynamics code called OPAL (Object oriented Particle Accelerator Library). In OPAL, the Monte Carlo simulations of Coulomb scattering and energy loss are performed seamless with the particle tracking. Beside the linear optics, the influence of the passive elements (e.g. degrader, collimators, scattering foils and air gaps) on the beam emittance and energy spread can be analysed in the new model. This allows for a significantly improved precision in the prediction of beam transmission and beam properties. The accuracy of the OPAL model has been confirmed by numerous measurements.Comment: 17 pages, 19 figure

Exact Gravity Duals for Simple Quantum Circuits

Holographic complexity proposals have sparked interest in quantifying thecost of state preparation in quantum field theories and its possible dualgravitational manifestations. The most basic ingredient in defining complexityis the notion of a class of circuits that, when acting on a given referencestate, all produce a desired target state. In the present work we build onstudies of circuits performing local conformal transformations in generaltwo-dimensional conformal field theories and construct the exact gravity dualto such circuits. In our approach to holographic complexity, the gravity dualto the optimal circuit is the one that minimizes an externally chosen costassigned to each circuit. Our results provide a basis for studying exactgravity duals to circuit costs from first principles.<br

Beam Optics Study for a Potential VHEE Beam Delivery System

VHEE (Very High Energy Electron) therapy can be superior to conventional radiotherapy for the treatment of deep seated tumours, whilst not necessarily requiring the space and cost of proton or heavy ion facilities. Developments in high gradient RF technology have allowed electrons to be accelerated to VHEE energies in a compact space, meaning that treatment could be possible with a shorter linac. A crucial component of VHEE treatment is the transfer of the beam from accelerator to patient. This is required to magnify the beam to cover the transverse extent of the tumour, whilst ensuring a uniform beam distribution. Two principle methodologies for the design of a compact transfer line are presented. The first of these is based upon a quadrupole lattice and optical magnification of beam size. A minimisation algorithm is used to enforce certain criteria on the beam distribution at the patient, defining the lattice through an automated routine. Separately, a dual scattering-foil based system is also presented, which uses similar algorithms for the optimisation of the foil geometry in order to achieve the desired beam shape at the patient location

Beam optics study for a potential VHEE beam delivery system

VHEE (Very High Energy Electron) therapy can be superior to conventional radiotherapy for the treatment of deep seated tumours, whilst not necessarily requiring the space and cost of proton or heavy ion facilities. Developments in high gradient RF technology have allowed electrons to be accelerated to VHEE energies in a compact space, meaning that treatment could be possible with a shorter linac. A crucial component of VHEE treatment is the transfer of the beam from accelerator to patient. This is required to magnify the beam to cover the transverse extent of the tumour, whilst ensuring a uniform beam distribution. Two principle methodologies for the design of a compact transfer line are presented. The first of these is based upon a quadrupole lattice and optical magnification of beam size. A minimisation algorithm is used to enforce certain criteria on the beam distribution at the patient, defining the lattice through an automated routine. Separately, a dual scattering-foil based system is also presented, which uses similar algorithms for the optimisation of the foil geometry in order to achieve the desired beam shape at the patient location

Design of beam optics and radiation protection concept for NA60+ heavy-ion experiment at CERN

NA60+ is a fixed target experiment proposed in the framework of the Physics Beyond Colliders programme at CERN. It aims to precisely measure the hard and electromagnetic probes in nuclear collisions. Initially proposed for the underground cavern ECN3 with very high beam intensities, the experiment now foresees a location in the EHN1 surface hall which was shown to have a limited impact on the physics performance in spite of a significant reduction of beam intensity and detector size. The potential installation and operation of the experiment with the ion beams from the Super Proton Synchrotron (SPS) has been examined regarding detector integration, beam physics, radiation protection and shielding requirements. The integration of the experiment is considered feasible, but would require a significant reconfiguration of the existing hall infrastructure with regards to shielding and layout

Physics Beyond Colliders:The Conventional Beams Working Group

The Physics Beyond Colliders initiative aims to exploit the full scientific potential of the CERN accelerator complex and its scientific infrastructure for particle physics studies, complementary to current and future collider experiments. Several experiments have been proposed to fully utilize and further advance the beam options for the existing fixed target experiments present in the North and East Experimental Areas of the CERN SPS and PS accelerators. We report on progress with the RF-separated beam option for the AMBER experiment, following a recent workshop on this topic. In addition we cover the status of studies for ion beams for the NA⁶⁰⁺ experiment, as well as of those for high intensity beams for Kaon physics and feebly interacting particle searches. With first beams available in 2021 after a CERN-wide long shutdown, several muon beam options were already tested for the NA64mu, MUonE and AMBER experiments

Establishment of the New Particle Therapy Research Center (PARTREC) at UMCG Groningen

After 25 years of successful research in the nuclear and radiation physics domain, the KVI-CART research center in Groningen is upgraded and re-established as the PARticle Therapy REsearch Center (PARTREC). Using the superconducting cyclotron AGOR and being embedded within the University Medical Center Groningen, it operates in close collaboration with the Groningen Proton Therapy Center. PARTREC uniquely combines radiation physics, medical physics, biology and radiotherapy research with an R&D program to improve hadron therapy technology and advanced radiation therapy for cancer. A number of further upgrades, scheduled for completion in 2023, will establish a wide range of irradiation modalities, such as pencil beam scanning, shoot-through with high energy protons and SOBP for protons, helium and carbon ions. Delivery of spatial fractionation (GRID) and dose rates over 300 Gy/s (FLASH) are envisioned. In addition, PARTREC delivers a variety of ion beams and infrastructure for radiation hardness experiments conducted by scientific and commercial communities, and nuclear science research in collaboration with the Faculty of Science and Engineering of the University of Groningen

Testing the Properties of Beam-Dose Monitors for VHEE-FLASH Radiation Therapy

Very High Energy Electrons (VHEE) of 50 - 250 MeV are an attractive choice for FLASH radiation therapy (RT). Before VHEE-FLASH RT can be considered for clinical use, a reliable dosimetric and beam monitoring system needs to be developed, able to measure the dose delivered to the patient in real-time and cut off the beam in the event of a machine fault to prevent overdosing the patient. Ionisation chambers are the standard monitors in conventional RT; however, their response saturates at the high dose rates required for FLASH. Therefore, a new dosimetry method is needed that can provide reliable measurements of the delivered dose in these conditions. Experiments using 200 MeV electrons were done at the CLEAR facility at CERN to investigate the properties of detectors such as diamond beam loss detectors, GEM foil detectors, and Timepix3 ASIC chips. From the tests, the GEM foil proved to be the most promising

Fuel pulverizing studies

Thesis (B.S.)--University of Illinois, 1920.Typescript