Apl. Prof. Dr. rer. nat. habil. Christoph Pascal Hugenschmidt

- Phone
- +49 89 289-14609
- Room
- –
- hugen@mytum.de
- Links
-
Homepage
Page in TUMonline
- Groups
- Neutron Scattering
Neutron Scattering - Job Title
- Adjunct Professor at the Physics Department
- Additional Info
- Professor Christoph Hugenschmidt Arbeitsgruppe Physik mit Positronen FRM II - Technische Universität München Lichtenbergstraße 1 D-85748 Garching phone +49 (0)89 289 14609 Christoph.Hugenschmidt@frm2.tum.de https://mlz-garching.de/positrons
Courses and Dates
Offered Bachelor’s or Master’s Theses Topics
- Analysis of the Material Properties during Precipitation Hardening of Al Alloys using Positrons
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Al alloys play a vital role in structural engineering. Many Al alloys gain their strength from precipitation hardening. The process of precipitate formation in Al alloys, however, is still not fully understood. For this purpose, an AlCuLi alloy is to be investigated using the positron beam at NEPOMUC/FRM II. Coincident Doppler broadening spectroscopy uses the positron as a micro probe in order to gain valuable information of the chemical environment of the positron annihilation site. This allows the investigation of vacancy-solute complexes and the formation of precipitates in Al alloys.
- suitable as
- Bachelor’s Thesis Physics
- Supervisor: Christoph Pascal Hugenschmidt
- Direct imaging of high-intensity positron beams with CCDs
- NEPOMUC provides the world’s highest intensity of low-energy positrons. The positron beam is applied for defect studies in materials science, surface investigations and fundamental research. Steering and optimization of the positron beam requires the use of beam monitors; ideally they should be fast, precise, reliable and inexpensive enough for them to be deployed in large numbers. Particle beam imaging is traditionally performed by amplifying the signal with micro channel plates, converting it through phosphor screens and then by recording the resulting image using a camera. Improvements in commercial charge-coupled devices (CCDs) and recent measurements on the conversion efficiency of positron beams by phosphor screens suggest, instead, the possibility of directly imaging the particle beam by modifying a CCD detector and placing it in the path of the positron beam. Preliminary measurements performed by our team seem to confirm this hypothesis. Your task will be that of working with the NEPOMUC team to further investigate the feasibility of imaging a positron beam by means of a modified commercial CCD detector.
- suitable as
- Bachelor’s Thesis Physics
- Supervisor: Christoph Pascal Hugenschmidt
- Erweiterung eines Spektrometers zur Messung der Positronenlebensdauer zur Bestimmung des freien Volumens in Kaffeebohnen
- Die Messung der Lebensdauer von Positronen (PALS) ist eine etablierte Methode zur Untersuchung von Defekten in kristallinen Materialien oder Nanoporen in Polymeren. Gemessene Positronenlebensdauern betragen typischerweise 100-200 ps. Unser PALS Spektrometer besteht aus einer Na-22 Quelle und schnellen Szintillationsdetektoren, deren Ausgabesignale mit einer Rate von 40 GSamples/s digitalisiert werden. Die Verarbeitung der so erzeugten Daten erfolgt offline durch einen Python-Code. Im Verlauf der Bachelorarbeit soll der Versuchsaufbau routinemäßig mit vier Detektoren betrieben werden. Um die Leistungsfähigkeit des Spektrometers zu demonstrieren, soll eine Messreihe zur Porengröße in Kaffeebohnen in Abhängigkeit des Röstgrades durchgeführt werden.
- suitable as
- Bachelor’s Thesis Physics
- Supervisor: Christoph Pascal Hugenschmidt
- Messung der Dopplerverbreiterung der Positronenannihilationslinie zur Charakterisierung von Dünnschichtsystemen
- Die Doppler-Verbreiterungsspektroskopie der Positronenannihilationsline (DBS) mit einem monoenergetischen Positronenstrahl ist eine hochsensitive Methode zur Charakterisierung von Gitterdefekten in oberflächennahen Schichten. Da verschiedene Materialien unterschiedliche Positronenaffinitäten aufweisen, lässt sich durch geschickte Kombination eine Grenzfläche herstellen, welche Positronen bevorzugt in eine Richtung passieren. Ziel der Bachelorarbeit ist es, eine Reihe solcher Dünnschichtsysteme mit DBS zu vermessen um deren Defektkonzentration und Güte zu bestimmen, sowie mit den gewonnen Daten das Auswerteprogramm LIMPID (Layer-wise Investigation of Measurements on Positron Implantation and Diffusion) zu verifizieren. Neben den DBS Messungen ist im Rahmen einer Kooperation mit der Arbeitsgruppe Plasma-Material-Wechselwirkung am MPI für Plasmaphysik geplant, Rutherford-Rückstreuspektrometrie (RBS) zur (destruktiven) Bestimmung der Schichtdicken einzusetzen.
- suitable as
- Bachelor’s Thesis Physics
- Supervisor: Christoph Pascal Hugenschmidt
Publications
- Formation of vacancies and metallic-like domains in photochromic rare-earth oxyhydride thin films studied by in-situ illumination positron annihilation spectroscopy
- Ziying Wu (author), Tom de Krom (author), Giorgio Colombi (author), Diana Chaykina (author), Gijs van Hattem (author), Henk Schut (author), Marcel Dickmann (author), Werner Egger (author), Christoph Hugenschmidt (author), Ekkes Brück (author), Bernard Dam (author), Stephan W. H. Eijt (author)
- 2022-06-21
- journal article
- Physical Review Materials
- DOI: 10.1103/PhysRevMaterials.6.065201
- Total-reflection high-energy positron diffractometer at NEPOMUC — Instrumentation, simulation, and first measurements
- Matthias Dodenhöft (author), Sebastian Vohburger (author), Christoph Hugenschmidt (author)
- 2021-11-01
- journal article
- Review of Scientific Instruments
- DOI: 10.1063/5.0062412
- Momentum density spectroscopy of Pd: Comparison of 2D-ACAR and Compton scattering using a 1D-to-2D reconstruction method
- Josef Ketels (author), David Billington (author), Stephen B. Dugdale (author), Michael Leitner (author), Christoph P. Hugenschmidt (author)
- 2021-08-30
- journal article
- Physical Review B
- DOI: 10.1103/PhysRevB.104.075160
- Injection of positrons into a dense electron cloud in a magnetic dipole trap
- M. Singer (author), M. R. Stoneking (author), E. V. Stenson (author), S. Nißl (author), A. Deller (author), A. Card (author), J. Horn-Stanja (author), T. Sunn Pedersen (author), H. Saitoh (author), C. Hugenschmidt (author)
- 2021-06
- journal article
- Physics of Plasmas
- DOI: 10.1063/5.0050881
- Absolute fraction of emitted Ps determined by geant4-supported analysis of gamma spectra
- B. Rienäcker (author), T. Gigl (author), G. Nebbia (author), F. Pino (author), C. Hugenschmidt (author)
- 2020-12-18
- journal article
- Physical Review A
- DOI: 10.1103/PhysRevA.102.062212
- Absolute fraction of emitted Ps determined by GEANT4 supported analysis of gamma spectra
- 2020-10-05
- other
- ARXIV: arXiv:2010.01854v1
- Annealing behaviors of vacancy-type defects in AlN deposited by radio-frequency sputtering and metalorganic vapor phase epitaxy studied using monoenergetic positron beams
- Akira Uedono (author), Kanako Shojiki (author), Kenjiro Uesugi (author), Shigefusa F. Chichibu (author), Shoji Ishibashi (author), Marcel Dickmann (author), Werner Egger (author), Christoph Hugenschmidt (author), Hideto Miyake (author)
- 2020-08-28
- journal article
- Journal of Applied Physics
- DOI: 10.1063/5.0015225
- Annealing behavior of open spaces in AlON films studied by monoenergetic positron beams
- 2018
- journal article
- Applied Physics Letters
- DOI: 10.1063/1.5027257
- Carrier Trapping by Vacancy-Type Defects in Mg-Implanted GaN Studied Using Monoenergetic Positron Beams
- 2018
- journal article
- physica status solidi (b)
- URL: http://dx.doi.org/10.1002/pssb.201700521
- DOI: 10.1002/pssb.201700521
- Impact and Applications: Positron Beam Experiments at NEPOMUC
- 2018
- journal article
- Nuclear Physics News
- DOI: 10.1080/10619127.2018.1463022
further publications (total of 132).
See ORCID profile of Christoph Pascal Hugenschmidt as well.