Imaging with protons at MedAustron Ulrich-Pur, F.; Bergauer, T.; Burker, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2020, Letnik:
978
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Ion beam therapy has become a frequently applied form of cancer therapy over the last years. The advantage of ion beam therapy over conventional radiotherapy using photons is the strongly localized ...dose deposition, leading to a reduction of dose applied to surrounding healthy tissue. Currently, treatment planning for proton therapy is based on X-ray computed tomography, which entails certain sources of inaccuracy in calculation of the stopping power (SP). A more precise method to acquire the SP is to directly use high energy protons (or other ions such as carbon) and perform proton computed tomography (pCT). With this method, the ions are tracked prior to entering and after leaving the patient and finally their residual energy is measured at the very end. Therefore, an ion imaging demonstrator, comprising a tracking telescope made from double-sided silicon strip detectors and a range telescope as a residual energy detector, was set up. First measurements with this setup were performed at beam tests at MedAustron, a center for ion therapy and research in Wiener Neustadt, Austria. The facility provides three rooms for cancer treatment with proton beams as well as one which is dedicated to non-clinical research.
This contribution describes the principle of ion imaging with proton beams in general as well as the design of the experimental setup. Moreover, first results from simulations and recent beam tests as well as ideas for future developments will be presented.
LGAD technology for HADES, accelerator and medical applications Krüger, W.; Bergauer, T.; Galatyuk, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2022, Letnik:
1039
Journal Article
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Low Gain Avalanche Diode (LGAD) technology has been used to design and construct prototype and full-size beam detector systems for applications requiring simultaneous time and spatial precision. For ...these purposes, a dedicated LGAD strip sensor production has been conducted at Fondazione Bruno Kessler (FBK) with different strip geometries and sizes. This contribution will review a wide variety of LGAD applications ranging from the reaction time (T0) detector for experiments utilizing proton and pion beams with the High Acceptance Di-Electron Spectrometer (HADES) at GSI in Darmstadt, Germany, to beam structure monitoring at the Superconducting DArmstadt LINear ACcelerator (S-DALINAC) at the Technische Universität Darmstadt operated in energy recovery mode and medical applications at the MedAustron facility in Wiener Neustadt, Austria. We will also give a prospect of further upgrade projects at GSI and FAIR facilities.
An extensive comparison of the path uncertainty in single particle tracking systems for ion imaging was carried out based on Monte Carlo simulations. The spatial resolution as function of system ...parameters such as geometry, detector properties and the energy of proton and helium beams was investigated to serve as a guideline for hardware developments. Primary particle paths were sampled within a water volume and compared to the most likely path estimate obtained from detector measurements, yielding a depth-dependent uncertainty envelope. The maximum uncertainty along this curve was converted to a conservative estimate of the minimal radiographic pixel spacing for a single set of parameter values. Simulations with various parameter settings were analysed to obtain an overview of the reachable pixel spacing as function of system parameters. The results were used to determine intervals of detector material budget and position resolution that yield a pixel spacing small enough for clinical dose calculation. To ensure a pixel spacing below 2 mm, the material budget of a detector should remain below 0.25 % for a position resolution of 200 \(\mathrm{\mu m}\) or below 0.75 % for a resolution of 10 \(\mathrm{\mu m}\). Using protons, a sub-millimetre pixel size could not be achieved for a phantom size of 300 mm or at a large clearance. With helium ions, a sub-millimetre pixel spacing could be achieved even for a large phantom size and clearance, provided the position resolution was less than 100 \(\mathrm{\mu m}\) and material budget was below 0.75 %.
Ion beam therapy has become a frequently applied form of cancer therapy over the last years. The advantage of ion beam therapy over conventional radiotherapy using photons is the strongly localized ...dose deposition, leading to a reduction of dose applied to surrounding healthy tissue. Currently, treatment planning for proton therapy is based on X-ray computed tomography, which entails certain sources of inaccuracy in alculation of the stopping power (SP). A more precise method to acquire the SP is to directly use high energy protons (or other ions such as carbon) and perform proton computed tomography (pCT). With this method, the ions are tracked prior to entering and after leaving the patient and finally their residual energy is measured at the very end. Therefore, an ion imaging demonstrator, comprising a tracking telescope made from double-sided silicon strip detectors and a range telescope as a residual energy detector, was set up. First measurements with this setup were performed at beam tests at MedAustron, a center for ion therapy and research in \mbox{Wiener Neustadt}, \mbox{Austria}. The facility provides three rooms for cancer treatment with proton beams as well as one which is dedicated to non-clinical research. This contribution describes the principle of ion imaging with proton beams in general as well as the design of the experimental setup. Moreover, first results from simulations and recent beam tests as well as ideas for future developments will be presented.
The replacement of the existing endcap calorimeter in the Compact Muon Solenoid (CMS) detector for the high-luminosity LHC (HL-LHC), scheduled for 2027, will be a high granularity calorimeter. It ...will provide detailed position, energy, and timing information on electromagnetic and hadronic showers in the immense pileup of the HL-LHC. The High Granularity Calorimeter (HGCAL) will use 120-, 200-, and 300-\(\mu\textrm{m}\) thick silicon (Si) pad sensors as the main active material and will sustain 1-MeV neutron equivalent fluences up to about \(10^{16}~\textrm{n}_\textrm{eq}\textrm{cm}^{-2}\). In order to address the performance degradation of the Si detectors caused by the intense radiation environment, irradiation campaigns of test diode samples from 8-inch and 6-inch wafers were performed in two reactors. Characterization of the electrical and charge collection properties after irradiation involved both bulk polarities for the three sensor thicknesses. Since the Si sensors will be operated at -30 \(^\circ\)C to reduce increasing bulk leakage current with fluence, the charge collection investigation of 30 irradiated samples was carried out with the infrared-TCT setup at -30 \(^\circ\)C. TCAD simulation results at the lower fluences are in close agreement with the experimental results and provide predictions of sensor performance for the lower fluence regions not covered by the experimental study. All investigated sensors display 60\(\%\) or higher charge collection efficiency at their respective highest lifetime fluences when operated at 800 V, and display above 90\(\%\) at the lowest fluence, at 600 V. The collected charge close to the fluence of \(10^{16}~\textrm{n}_\textrm{eq}\textrm{cm}^{-2}\) exceeds 1 fC at voltages beyond 800 V.
The Compact Linear Collider (CLIC) is a proposed future high-luminosity linear electron-positron collider operating at three energy stages, with nominal centre-of-mass energies: 380 GeV, 1.5 TeV, and ...3 TeV. Its aim is to explore the energy frontier, providing sensitivity to physics beyond the Standard Model (BSM) and precision measurements of Standard Model processes with an emphasis on Higgs boson and top-quark physics. The opportunities for top-quark physics at CLIC are discussed in this paper. The initial stage of operation focuses on top-quark pair production measurements, as well as the search for rare flavour-changing neutral current (FCNC) top-quark decays. It also includes a top-quark pair production threshold scan around 350 GeV which provides a precise measurement of the top-quark mass in a well-defined theoretical framework. At the higher-energy stages, studies are made of top-quark pairs produced in association with other particles. A study of ttH production including the extraction of the top Yukawa coupling is presented as well as a study of vector boson fusion (VBF) production, which gives direct access to high-energy electroweak interactions. Operation above 1 TeV leads to more highly collimated jet environments where dedicated methods are used to analyse the jet constituents. These techniques enable studies of the top-quark pair production, and hence the sensitivity to BSM physics, to be extended to higher energies. This paper also includes phenomenological interpretations that may be performed using the results from the extensive top-quark physics programme at CLIC.
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