"... statt um Fakten und abstrakte Prozesse ging es mal um uns.": Lehr-Lern-Projekte für Medizinstudierende in Sachsen

Die Aufnahme eines universitären Studiums bedeutet in vielerlei Hinsicht eine Umstellung. Die Studierenden müssen die Anpassung an eine neue, meist ungewohnte Lernumgebung bewältigen. Diese wartet mit einem höheren Leistungsniveau und einer komprimierten Darbietung von Lernstoff auf. Zumeist werden die Themen sehr inhaltsbezogen und in unterschiedlichen Formen unterrichtet. Eine selbständige sowie langfristige Zeitplanung ist dabei vonnöten ebenso wie selbstorganisiertes Arbeiten. Zudem sind die Unterscheidung von wichtigen und unwichtigen Inhalten sowie der Umgang mit fakultativen Veranstaltungen im Studium essenziell. Diese Kompetenzen werden zu Studienbeginn überwiegend vorausgesetzt. Die Problematik der Anpassung betrifft dabei auch und insbesondere Studierende der Medizin

Development of an IH-type linac for the acceleration of high current heavy ion beams

The Facility for Antiproton and Ion Research (FAIR) at GSI Darmstadt will provide unprecedented intensities of protons and heavy ions up to uranium at energies of up to 29 GeV for protons and 2.7 GeV/u for Uranium 28+. To achieve high intensities in the synchrotron accelerators, high beam currents have to be provided by the injector linear accelerators. High current heavy ion beams are provided by the Universal Linear Accelerator (UNILAC), which in its current state will not be able to provide the required FAIR beam currents. This thesis deals with the development of upgrades for the UNILAC to ensure its high current capability. The first improvement is a matching section (MEBT) for the interface between the RFQ and the IH-DTL of the existing high current injector HSI at the UNILAC. With this new MEBT section, particle losses are eliminated and the overall beam quality is improved. As a second improvement, a complete replacement of the existing Alvarez-DTL is presented. A combination of efficient IH-type cavities and KONUS beam dynamics results in a reduction of the linac length from about 60 m (Alvarez) to just 23 m (new IH-DTL) while providing the same energy and fulfilling FAIR requirements of a high beam current and beam quality. This thesis contains a detailed beam dynamics design of the new linac including some fundamental investigations of the KONUS beam dynamics concept. A cross-check of the beam dynamics design was performed with two independent multi-particle simulation codes. Detailed error studies were conducted to investigate the influence of manufacturing, alignment and operating errors on the beam dynamics performance. Additionally, all five linac cavities were designed, optimized, and their RF parameters including power requirements calculated to provide a comprehensive linac design.Diese Arbeit befasst sich mit der Entwicklung von Linearbeschleunigern für Schwerionen. Insbesondere werden in dieser Arbeit zwei Abschnitte des GSI Schwerionenbeschleunigers UNILAC neu entworfen um höhere Ionenströme beschleunigen zu können..

First 3D Printed IH-Type Linac Structure—Proof-of-Concept for Additive Manufacturing of Linac RF Cavities

Additive manufacturing (AM or “3D printing”) has become a powerful tool for the rapid prototyping and manufacturing of complex part geometries. Especially interesting for the world of particle accelerators is the process of the 3D printing of stainless steel (and copper) parts. We present a first prototype of a 433 MHz IH-type linac cavity with an internal drift tube structure manufactured by metal 3D printing. The prototype cavity has been constructed to act as a proof-of-concept for the technology. In this paper we present the concept of the cavity as well as first results of vacuum testing and materials testing

First 3D Printed IH-Type Linac Structure—Proof-of-Concept for Additive Manufacturing of Linac RF Cavities

Additive manufacturing (AM or “3D printing”) has become a powerful tool for the rapid prototyping and manufacturing of complex part geometries. Especially interesting for the world of particle accelerators is the process of the 3D printing of stainless steel (and copper) parts. We present a first prototype of a 433 MHz IH-type linac cavity with an internal drift tube structure manufactured by metal 3D printing. The prototype cavity has been constructed to act as a proof-of-concept for the technology. In this paper we present the concept of the cavity as well as first results of vacuum testing and materials testing

The KONUS IH-DTL proposal for the GSI UNILAC poststripper linac replacement

Motivated by the necessary replacement of the GSI UNILAC poststripper linac, a compact and efficient linac design based on IH-type cavities has been developed. Using KONUS beam dynamics, it was possible to design a linac consisting of only five cavities that can be operated by the existing UNILAC RF amplifier structure. The transversal focusing scheme is based on magnetic quadrupole triplet lenses. The optimized design provides full transmission and low emittance growth for the design current of 15 emA U28+, accelerating the beam from 1.4 MeV/u to 11.4 MeV/u. Extensive error studies were performed to define tolerances and verify the stability of the design with respect to misalignment and injection parameters. The design provides a compact and cost effective alternative to a new Alvarez linac. With a total length of just 22.8 meters it will leave room for future energy upgrades in the UNILAC tunnel

Additive Manufacturing of an IH-Type Linac Structure from Stainless Steel and Pure Copper

Additive manufacturing (AM) of metals has the potential to provide significant benefits for the construction of future particle accelerators. The combination of low cost manufacturing of complex geometries in combination with efficiency gains from improved linac design enabled by AM may be one way towards future cost-effective green accelerator facilities. As a proof of concept, we present a high-efficiency Zeff=280 MΩ/m, 433.632 MHz IH-DTL cavity based on an AM design. In this case, the complex internal drift tube structures with internal cooling channels have been produced from 1.4404 stainless steel and from pure copper using AM. The prototype cavity, as well as stainless steel AM parts have been electroplated with copper. We present results from successful vacuum tests, low level RF measurements of the cavity, as well as the status of preparations for high-power RF tests with a 30 kW pulsed power amplifier

"... statt um Fakten und abstrakte Prozesse ging es mal um uns.": Lehr-Lern-Projekte für Medizinstudierende in Sachsen

Die Aufnahme eines universitären Studiums bedeutet in vielerlei Hinsicht eine Umstellung. Die Studierenden müssen die Anpassung an eine neue, meist ungewohnte Lernumgebung bewältigen. Diese wartet mit einem höheren Leistungsniveau und einer komprimierten Darbietung von Lernstoff auf. Zumeist werden die Themen sehr inhaltsbezogen und in unterschiedlichen Formen unterrichtet. Eine selbständige sowie langfristige Zeitplanung ist dabei vonnöten ebenso wie selbstorganisiertes Arbeiten. Zudem sind die Unterscheidung von wichtigen und unwichtigen Inhalten sowie der Umgang mit fakultativen Veranstaltungen im Studium essenziell. Diese Kompetenzen werden zu Studienbeginn überwiegend vorausgesetzt. Die Problematik der Anpassung betrifft dabei auch und insbesondere Studierende der Medizin

"... statt um Fakten und abstrakte Prozesse ging es mal um uns.": Lehr-Lern-Projekte für Medizinstudierende in Sachsen

Die Aufnahme eines universitären Studiums bedeutet in vielerlei Hinsicht eine Umstellung. Die Studierenden müssen die Anpassung an eine neue, meist ungewohnte Lernumgebung bewältigen. Diese wartet mit einem höheren Leistungsniveau und einer komprimierten Darbietung von Lernstoff auf. Zumeist werden die Themen sehr inhaltsbezogen und in unterschiedlichen Formen unterrichtet. Eine selbständige sowie langfristige Zeitplanung ist dabei vonnöten ebenso wie selbstorganisiertes Arbeiten. Zudem sind die Unterscheidung von wichtigen und unwichtigen Inhalten sowie der Umgang mit fakultativen Veranstaltungen im Studium essenziell. Diese Kompetenzen werden zu Studienbeginn überwiegend vorausgesetzt. Die Problematik der Anpassung betrifft dabei auch und insbesondere Studierende der Medizin

Commissioning status of the Frankfurt Neutron Source FRANZ LEBT and RFQ

The Frankfurt Neutron Source FRANZ will be a compact accelerator driven neutron source utilizing the 7Li(p,n)^7Be reaction with a 2 MeV proton beam. Recent comissioning efforts showed succesful proton beam operation at the targeted RFQ injection energy of 60 keV up until the point of RFQ injection. The RFQ was retrofitted with new electrodes for the injection energy of 60 keV. We report on the status of comissioning of the beamline and RFQ

Upgrade and Commissioning of the 60 keV Low Energy Beam Transport Line for the Frankfurt Neutron Source FRANZ

The Low Energy Beam Transport line (LEBT) for the Frankfurt Neutron Source (FRANZ) has been redesigned to accommodate a 60 keV proton beam. Driven by a CHORDIS ion source, operating at 35 kV, a newly designed electrostatic postaccelerator has beeen installed to reach the desired beam energy of 60 keV. Additional upgrades to the beamline include two steerer pairs, several optical diagnostics sections and an additional faraday cup. We present the results of beam commissioning up to the point of RFQ injection. Emittance measurements were performed to prepare matching to the RFQ and improve the beam dynamics model of the low energy beamline. Due to the successful operation of the beamline at 60 keV, retrofitting of the RFQ for the new energy has been initiated