Doctorate in Applied and Engineering Physics  

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Thesis Proposal for the

Doctorate Program in Applied and Engineering Physics (DAEPHYS)

Starting in the Academic Year 2016/2017


Proposal 036


Title:Development of an X-ray spectrometer for measurements of electron impact ionization cross sections of highly charged ions
 
Objectives (recommended length: 2000-3000 char):
The knowledge of electron impact ionization cross sections of highly charged ions is extremely important in modelling astrophysic plasma processes, such as star formation and explosion [1] as well as in magnetic confinement fusion [2]. The interpretation of astrophysical spectra, dominated by collisional processes, is based essentially in the knowledge of the plasma charge state distribution, whose shape depends on the balance between the electronic impact and electronic recombination, as well as the radiative and radiationless transitions.
In most cases the astrophysical plasma simulation codes are based on atomic parameters calculated with, complex or otherwise, ab initio codes. In the case of ionization, there is almost no experimental results for the sub-shell resolved cross sections of highly charged ions.

The goal of this work is to design and construct a state-of-the-art X-ray spectrometer to be later coupled to an ion source in order to measure sub-shell resolved inner shell electron impact ionization cross sections. The spectrometer will consist of an electron gun with a micro beam and deflector plates which will allow a scan of the crossed ion beam, extracted from an Electron Cyclotron Resonance Ion Source [3].

The X-ray detector that will collect the radiation coming from the ion de-excitation cascade is an Amptek XR-100SDD with a detection area of 25mm2 and 500 µm thickness with a Be window of 25 µm [4]. The system will be built and tested at the Atomic and Molecular Physics Laboratory of the physics department in FCT UNL and later will be assembled at the extraction line of the highly charged ions source “Source d'Ions Multicharges de Paris” (SIMPA).



[1] K. P. Dere, Astronomy & Astrophysics 466, 771–792 (2007)
[2] A. Borovik, D. Schury, B. Ebinger, K. Spruckz, A. Beckerz, M. F. Gharaibehx, J. Rausch, S. Schippers, A. Muller, Journal of Physics: Conference Series 635, 052040 (2015)
[3] M. Guerra, P. Amaro, C. I. Szabo, A. Gumberidze, P. Indelicato and J. P. Santos, “Analysis of the charge state distribution in an ECRIS Ar plasma using high-resolution x-ray spectra”, J. Phys. B: At. Mol. Opt. Phys. 46 065701, (2013)
[4] M. Guerra, M. Manso, S. Longelin, S. Pessanha and M. L. Carvalho, “Performance of three different Si X-ray detectors for portable XRF spectrometers in cultural heritage applications”, Journal of Instrumentation, 7, C10004 (2012)
 
Framework (recommended length: 500-2000 char):
The LIBPhys-UNL team has a large experience in X-ray spectrometry of highly charged ion plasmas, and also of electron impact calculation and measurement using crossed beams.
All of the required equipment for the construction of this spectrometer, apart from the electron gun which will have to be acquired, already exists in the Department of Physics of the Universidade Nova de Lisboa (UNL).
 
Tasks (recommended length: 1000-3000 char):
1. Bibliographic study of X-ray spectrometry of highly charged ions plasmas
2. Design of the spectrometer and the charge collector;
3. Construction of the spectrometer;
4. Test and characterization of the electron beam (shape, flux, etc..);
5. Test of the spectral quality for ionization of atomic beams of rare gases;
6. Test of the spectral quality for ionization of lowly charged ion beams;
7. Measurements of total and partial electron impact ionization cross sections in highly charged Ar ions;
8. Dissertation writing
 
Research centre/lab or R&D unit hosting the thesis project:
LIBPhys-UNL
 
University to which the thesis project will be presented:
UNL - Universidade Nova de Lisboa
 
DAEPHYS Scientific Domain in which the project fits:
Metrology
 
Relation of the project to the Scientific Domains of DAEPHYS:
This proposal aims at constructing an X-ray spectrometer for sub-shell resolved electron impact cross section measurements in highly charged ions. The system will be design, built and tested at FCT UNL and later coupled to the highly charged ions extraction line of SIMPA at the Laboratoire Kastler Brossel in Paris.
 
Candidate profile:
It is expected that the candidate has some knowledge of atomic physics and/or ion beams as well as data evaluation.
 
Does this proposal involve more than one University?:
no
 
Synergies between the two Universities participating in the proposal:
DAEPHYS strongly encourages the presentation of thesis projects in co-supervision by researchers from two of the universities participating in the Program. In this field, explain the benefits resulting from the proposed co-supervision and the involvement of elements from the two universities, e.g. building critical mass teams, profiting from existing infrastructures or advanced equipments, profiting from expert technical know-how, etc. If the proposal involves only one University, write n/a.
(recommended length: 500-1000 char)
: n/a
 
Does this proposal involve a company?:
no
 
Proposals involving a company:
DAEPHYS strongly encourages the presentation of thesis projects involving a company, preferably a high-tech company. These proposals have to: 1) be centered on a technological problem in which the partner company has been (or plan / would like to be) involved; 2) have a co-supervisor on the enterprise; 3) include part of the project to be carried out in the company.
(recommended length: 500-1000 char)
:

 

Supervisor

Name:Mauro António Moreira Guerra
Institution:Universidade Nova de Lisboa
email:mguerra@fct.unl.pt
 
link to CV or indication of ORCID ID:
0000-0001-6286-4048

 

Co-Supervisor

Name:José Paulo Moreira dos Santos
Institution:Universidade Nova de Lisboa
email:jps@fct.unl.pt
 
link to CV or indication of ORCID ID:
0000-0002-8363-0109

 

Uploaded PDF document: proposal-036.pdf