Doctoral Student (m/f/d) in Physics for FE-FRT Design to Compensate Transient Beam Loading in 3rd Harmonic BESSY II/III Cavities Reference No.: BE 2024/18 Bessy II is a synchrotron based light source used for cutting edge research in a wide range of fields including spectroscopy, microscopy and protein structure analysis. Radio-frequency cavities operating at three times the frequency of the main accelerating cavities are used to lengthen the particle bunches in order to increase the beam lifetime. However, due to a gap in the particle beam (which is highly desirable for users) transient beam loading occurs which impacts the achievable beam lifetime improvement. FE-FRTs are a nascent type of RF cavity tuner which can control the cavity frequency by applying a voltage across a ferroelectric material. The non-mechanical nature of FE-FRTs allows the frequency of cavities to be controlled orders of magnitude faster (100s ns or less) than with existing tuner technologies and for the first time opens up the ability to compensate for transient beam loading. The idea to use FRTs to compensate transient beam loading was only very recently developed at CERN in the context of the HL-LHC upgrade, we aim to apply this idea in the even more challenging case of compact light source machines with significantly higher RF and revolution frequencies. For BESSY II and the proposed upgrade BESSY III, this would allow for significant improvements of the beam lifetime. Significant RF design and engineering challenges must be overcome to demonstrate that this approach is practical. However, if successful, this technique could be adopted worldwide in similar machines facing the same challenges. Your Tasks You will design, build and test an FE-FRT suitable to compensate transient beam loading in BESSY II/III. You will study the integration of this FE-FRT with 3rd Harmonic 1.5 GHz normal conducting cavities for the existing BESSY II and proposed BESSY III accelerators. You will study the integration of this tuner with a high voltage pulser being designed in parallel, adapting the FE-FRT design as necessary to ensure proper functioning of the complete system. You will investigate through analysis, simulation and experiment the expected beam lifetime improvement that could be achieved by using an FE-FRT for various operational scenarios of BESSY II and III. You will also get the opportunity to attend an accelerator school such as CAS or USPAS and to present your work at conferences and workshops. Your Profile Master's degree or diploma in physics, or equivalent. Engineering or electronics degrees will also be considered. Demonstrated ability to use creativity and/or apply knowledge from another area to solve difficult problems. Strong mathematical ability coupled with a keen physical intuition and excellent experimental skills. Highly proficient in English with excellent communication skills. Highly motivated and organised. Good interpersonal skills, with the ability to work both independently and as part of a team. Of advantage would be: Knowledge of RF, electronics or accelerator physics Programming ability, especially Python Familiarity with RF simulation tools such as HFSS or CST etc. Your Benefits Contribution to innovation: work with researchers from around the world on projects that drive renewable energy and advanced technologies. Commitment to diversity: sustainability through an inclusive working environment, promotion of diversity sensitivity and implementation of sustainable and climate-neutral methods Career-enhancing networking opportunities: individual mentoring and support from the HZB Graduate Centre and HZB Postdoc Office Attractive remuneration through payment according to the Collective Wage Agreement for the Civil Service TVöD Bund Flexible working conditions: enjoy a 39-hour work week, 30 days of vacation, and the possibility to work remotely up to three days per week. Extensive additional benefits: a company pension plan (VBL), subsidy for public transport (Deutschlandticket Job) and company sports programmes Work-life-balance: access comprehensive advisory services to balance work and personal life, plus participate in company sports and wellness programs. Team spirit: be part of a welcoming and supportive team that looks forward to working with you Fixed term contract for 48 months. The salary is based on the Collective Agreement for the German Public Service (TVöD-Bund). How to apply We look forward to receiving your application via our application management system by 24.11.2024. For reasons of data protection regulations, we are unfortunately unable to consider applications that reach us by other means (such as email or mail) in the application process. We very much want our workplace to be diverse, and welcome applications from people with different backgrounds. It is our mission to promote equal opportunities and to improve women’s representation in the workforce. We are therefore very interested in receiving applications from women. Where the qualifications are met, we will give preference to people with disabilities. Helmholtz-Zentrum Berlin für Materialien und Energie GmbH Hahn-Meitner-Platz 1, 14109 Berlin www.helmholtz-berlin.de ➜ APPLY HERE Climate change poses serious challenges to the whole world. 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