In collaboration with the Imperial College London:
PhD Studentship concerning spectroscopic studies of highly charged ions (HCI) held in a
Penning ion trap in the framework of the HITRAP project (pdf, 20 KB)
other PhD positions:
PhD at GSI Darmstadt, Germany, with the topic: Laser spectroscopy of Be-like krypton ions at the ESR to the job offer ...>
Practical trainings
On request we offer several days training courses in our labs on each of the topics listed
above. In this way every interested student can get an impression of the working field, the
working conditions and our group
Diploma/Master thesis (University of Applied Sciences) at the SPECTRAP experiment:
The SPECTRAP trap allows axial access for
ions and laser beams and radial access
for observation of the fluorescence
We are looking for a diploma/master student (University of Applied Sciences) who
intends to write a diploma/master thesis in the field of experiment control / data
acquisition. The SPECTRAP experiment at GSI Helmholtzzentrum für Schwerionenforschung,
Darmstadt, Germany offers a variety of experimental techniques in the field of
ultra high vacuums, cryotechniques, particle traps, superconducting magnets, lasers,
fluorescence detectors and their control by PC based LabView applications.
It is concretely planned to develop, implement and operate a uniform control and data
acquisition system for the existing experiment. Typical used instruments are highly
precise cryoelectronics for nondestructive particle detection, precision voltage
sources, frequency and signal generators, high voltage sources, GPIB bus systems,
spectrum and network analyzers as well as several control devices for the operation
of the experiment. In the SPECTRAP experiment external generated highly charged ions
like U91+ are trapped in a so-called Penning trap and stored there in ultra high
vacuum and at cryogenic temperatures at 4 Kelvin. Scientific background of this
procedure is the precise laser spectroscopy of the optical transitions in such ions
which allows for conclusions about several electrical and nuclear properties and the
determination of fundamental constants. The experiment is part of the HITRAP project
of GSI which deals with precision measurements on highly charged ions.
More information can be found here
and at http://www.gsi.de/forschung/ap/index_e.html
The suited candidate should have general knowledge and interest in electronics and
computers and basic knowledge about controlling and data acquisition at experiments
like the one described here. Interested students are invited to view the experimental
setup and obtain more information. The thesis possibly also can be offered as bachelor
thesis.
Description:
You will need to set up a "frequency doubling stage" for a commercial dye
laser system, in order to generate pulsed laser light (UV, ~276 nm) for laser
spectroscopy of Be-like krypton ions. In this experiment we aim to test state-of-the-art
atomic structure calculations in 4-electron ions (84Kr32+), where correlation effects
play an important role. We hope to perform the experiment in 2012, at the Experimental
Storage Ring (ESR) of GSI in Darmstadt, and are currently starting the preparations.
To guide the laser light from the laser lab to the ESR over a distance of ~60 m, a
commercial "laser beam stabilization system" is available. Using fast electronics and
optomechanics, this system can stabilize continuous and pulsed lasers over larger
distances, thereby compensating for external disturbances (optics, air flow, etc.).
However, its useability for the UV-range has to be demonstrated and characterized.
This will be your second task.
Fields of activity: lasers, optics, optomechanics, electronics
Task: Development of an ion source for radioisotopes at TRIGA Project:TRIGA-Laser
Description:
At the TRIGA reactor a new ion source for the spectroscopic experiments
(TRIGA-Trap and TRIGA-Laser) with radioactive isotopes has to be set up as an alternative
for the currently constructed ECR source. Therefore, a combination of a surface and
plasma ion source is in preparation which has to be completed, to be connected to the reactor
and to be specified within the diploma thesis.
Furthermore, the feasibility of a so called gas cell in combination with a
sextupole ion guide for the production and transport of the radioactive ions
has to be investigated by use of computer-based simulations.
Fields of activity: ion sources, production of radioactive isotopes, mechanics,
CAD drawings, simulation software
Task: Setup of an iodine wavelength stabilization for fiber laser Project:SPECTRAP
Description:
An existing laser setup for laser cooling of Mg ions has to be wavelength-stabilized to
a molecular transition line in an iodine cell. Therefore, an iodine system which has been constructed
during preliminary work has to be reworked and to be adapted to the wavelengths in Mg.
Within the thesis spectra in a Penning trap have to be recorded.
Furthermore, if necessary implementation of the laser wavelength control and the laser
beam position control into an existing LabView experiment control software.
Fields of activity: laser spectroscopy, handling of lasers, electronics, optics
Task: Methods of stabilization of a ring laser for laser spectroscopy at TRIGA reactor Project:TRIGA-Laser
Description:
For laser spectroscopy of radioactive isotopes at the TRIGA reactor a continuous
Titanium:Sapphire laser is used. In order to guarantee stable operation this laser has
to be operated and stabilized in a laser laboratory outside of the reactor hall.
In addition to the stabilization of this laser relative to a frequency comb and
by comparison relative to an existing iodine cell, the laser light has to be transported
by means of fiber technology into the reactor hall which is 150 m away.
Furthermore, within the diploma thesis the stability of the currently used (old) Titanium:Sapphire laser -- when
stabilized relative to the iodine cell -- has to be compared directly with the new
Titanium:Sapphire laser of the latest generation which will be used for the
TRIGA experiments in the future.
Fields of activity: laser spectroscopy, handling of lasers, stabilization control circuit,
electronics, optics
Subject of the thesis:
Accurate laser spectroscopy measurements of exotic ions can test the fundamental theory
of QED (quantum electrodynamics) in the strongest electromagnetic fields available. Such
strong fields naturally exist close to the nuclei of atoms which are almost completely
stripped of their electrons, the so-called highly charged ions. These species can now be
created in a laboratory (GSI, Darmstadt) and made available for very interesting experiments
like these (HITRAP). By accurate measurements of the electronic structure very close to
the nucleus, it is possible to obtain information on the effects predicted by QED. A
successful PhD thesis would thus result in the best and unique measurements of (higher order)
QED effects in strong electromagnetic fields.
Experiences you will gain:
Vacuum techniques, superconducting magnet, cryogenic techniques, particle trapping
(Penning ion trap), particle manipulation and detection and cooling, different continuous
wave laser systems, high-precision laser spectroscopy, ion sources and ion optics.
Furthermore, you will have the opportunity to work in one of the world's best laboratories for
experiments with exotic ions. You will work in a team of excellent scientists with many
different nationalities (multi-cultural). This project takes place within the framework of
European-funded research (HITRAP), and we collaborate with well-known research groups from
all over the world (UK, Russia, USA).
Prerequisites:
The interested student should have followed a lecture on atomic physics, and thus have
knowledge of (hyper)fine structure and the principle of a laser. Previous experience with,
or a strong interest in, particle trapping or laser spectroscopy is appreciated. The candidate
occasionally needs to supervise younger (project) students and work independently
(most of the time).
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