PhD student in Atomic Physics:  Experimental studies of reactive charge transfer processes for complex molecules

The Department of Physics is located in the AlbaNova University Center and has approximately 240 employees, 250 students at undergraduate level and 70 graduate students. There are four research subjects within the postgraduate program: Physics, Theoretical Physics, Chemical Physics and Medical Radiation Physics. These subjects span over several research groups with different research activities. For information about the Department of Physics, see: The Department of Physics.

Project description

Subject: Physics

The Atomic Physics division at Stockholm University invites applicants for a Ph.D. position to carry out research at the DESIREE facility at the Department of Physics. DESIREE (Double ElectroStatic Ion Ring ExpEriment) is the only instrument available world-wide in which positive and negative ions may be stored and brought to interact with each other at very low relative velocities in a merged-beams configuration. This is achieved in a cold (13 K) environment that allows for long-time storage (up to hours) to ensure that the ions relax to their lowest energy quantum states before the interaction.

Experiments at DESIREE span a wide field of fundamental atomic/molecular collision physics and several areas of applications including but not limited to: interstellar ion chemistry, physics of stellar atmospheres, ion chemistry of the atmosphere of Earth and of e.g. the Saturn moon (Titan), stability and dynamics of biomolecules and of carbon and hydrocarbon molecules ranging in size from diatomic molecules and small chains to complex molecules such as e.g. fullerenes, Polycyclic Aromatic Hydrocarbons (PAHs) and clusters thereof. In parallel to the experimental work, members of the local research group develop theoretical models by which the interactions are described analytically or by advanced numerical methods.

In this project, we will investigate reactive charge-transfer (RCT) processes at DESIREE as part of a project funded by the Knut and Alice Wallenberg Foundation. The present experimental PhD position focuses on RCT for complex molecular systems that have been identified or are believed to be abundant in various astrophysical environments. For example carbon chains, fullerenes (C60 and C70), and PAHs. There are, in addition a PhD opening for experimental studies of RCT with small molecules and also a theoretical PhD position is to be filled, which is concerned with studies of RCT.

Since 2020, we have studied charge transfer between oppositely charged ions at DESIREE. The combination of merged positive/negative ion beams and long storage times allows for a unique degree of control of the initial states and the relative motion of the ions. Early studies were on atomic ions only, but more recently, we have also considered molecular ions. For those, electron transfer may be accompanied by chemical rearrangement, which we refer to as RCT. RCT processes are likely important in many cold plasma environments such as the interstellar medium.

In order to improve the already unique experimental conditions for RCT studies, we are introducing an energy-sensitive detection technique based on µ-calorimetry and developed in collaboration with research groups at Heidelberg University and the Max-Planck Institute for Nuclear Physics. This will be developed in parallel to the studies here and can likely be applied toward the end of the PhD period.

We seek a self-motivated candidate who is fluent in English. A keen interest in science in the broad sense and in the particular fields of research is taken for granted. An experimental background and skills in computational analysis and modeling methods are merits.

Qualification requirements

In order to be admitted to postgraduate education, the applicant must have the general and specific entry requirements. The qualification requirements must be met by the deadline for applications.

You meet general entry requirements if you have completed a second-cycle degree, or completed courses equivalent to at least 240 higher education credits, of which 60 credits must be in the second cycle, or have otherwise acquired equivalent knowledge in Sweden or elsewhere.

Specific entry requirements. In order to be accepted as a PhD student in Physics or Theoretical Physics a BSc in Physics (or equivalent) is required. The studies must include 60 credits of second-cycle courses in physics out of which at least 15 credits correspond to a second-cycle degree project. The degree project does not have to have been examined at the application deadline, but work corresponding to half a semester of full-time studies should have been devoted to it. For the subject Chemical Physics courses in chemistry may replace the required physics courses. The subject Medical Radiation Physics requires a second-cycle degree project of 30 credits in the subject area, or with 60 credits of physics, a second-cycle degree project of 30 credits in another subject area.

In addition, proficiency in English language, equivalent to English B in Swedish high school, is required, or

• Previously completed University degree taught in English
• IELTS score (Academic) of 6.0 or more (with none of the sections scoring less than 5.0)
• TOEFL score of 550 or more (computer based test 213, internet based 79)
• Cambridge/Oxford - Advanced or Proficiency level.

Selection

The selection among the eligible candidates will be based on their capacity to benefit from the training. The following criteria will be used to assess this capacity:

• documented knowledge in a relevant field of research
• capacity for analytical and creativ thinking
• initiative
• independence
• ability to collaborate
• written and oral proficiency.

Admission Regulations for Doctoral Studies at Stockholm University.

About the employment

We offer a fixed-term employment as a doctoral student according to Chapter 5 of the Higher Education Ordinance (1993:100). The period of employment may not be longer than what corresponds to full-time doctoral education for four years. As a doctoral student, you should primarily devote yourself to your own doctoral education, but the employment may include work with education, research and administration to a limited extent (maximum 20 %).

A new employment as a doctoral student is for a maximum of one year, the employment is then renewed for a maximum of two years at a time.

Stockholm University strives to be a workplace free from discrimination and with equal opportunities for all.

Contact

For more information about the project, please contact Prof. Henning Zettergren, henning@fysik.su.se.

For information about the employment Prof. Michael Odelius, odelius@fysik.su.se, who can also forward questions to the PhD student council at Fysikum.

Application

Apply for the PhD student position at Stockholm University's recruitment system. Attach a personal letter and CV as well as the attachments requested in the application form. It is the responsibility of the applicant to ensure that the application is complete in accordance with the instructions in the job advertisement, and that it is submitted before the deadline.

The instructions for applicants are available at: How to apply for a position.