Experimental Techniques on Molecular Physics

General characterization

Prerequisites

Previous knowleadge in:

Quantum mechanics

Atomic Physics

Molecular Physics

Vacuum and Charged Particles Technologies

Instrumentation

Bibliography

• Gaseous Molecular Ions, E Illenberger, J Momigny, Springer Verlag NY, 1992.
• Atomic and Molecular Collisions, Sir Harrie Massey, Taylor and Francis, Ltd., 1979.
• Molecular Reaction Dynamics and Chemical Reactivity, R D Levine and R Bernstein, Oxford University Press, 1987.
• Atomic collisions, McDaniel E. W.; Mitchell J. B. A.; Eugene Rudd M., John Wiley & Sons, INC.
• Electron molecule interactions and their applications (Vol1 and Vol2), Christophorou L. G., Academis Press
• Mass spectrometry principles and applications, Hoffmann E.; Stroobant V., John Wiley & Sons, INC

Teaching method

In this course, the active participation of the students will be stimulated, leading to a close collaboration with the lecturer and having a personal development of learning processes and scientific formation. The topics will be exposed in order to create in the students interrogative opportunities leading to answers and conclusions.

The course will be lectured weekly in theoretical classes (2h / week through zoom platform) during 14 weeks semester period. In the theoretical classes the topics are exposed to the students by means of theoretical and experimental results. Published studies will be used not only as bibliography, but also as lecturing material. In the end of semester, the students are invited to present a 20 min seminar within the lectured topics, as well as to discuss a scientific paper by means of a poster presentation.

Evaluation method

Evaluation deals with three lectures components (TP), where all will contribute to the final mark;

Attendance: students will have to attend at least 2/3 of the lectures (TP) which not include evaluation and the final mark and be approved in the seminar and poster presentation components (described below).

EVALUATUION:

a)    Test (T) or Exam (E), the mark will be obtained through a written test or written exam with a mark (NT) or (NE) equal or greater than 9.5 out of 20. This mark will be displayed with one decimal place.

b)    Scientific paper (C ) presentation (groups up to 3 students) with a mark (NC) equal or greater than 9.5 out of 20. This mark will be displayed with one decimal place. Once obtained the student will keep it for just one academic year;

c)    Seminar (S) presentation (groups up to 3 students) with a mark (NS) equal or greater than 9.5 out of 20. This mark will be displayed with one decimal place. Once obtained the student will keep it for just one academic year;

The final grade (NF), the students should have attendance to the course and final grade NF ≥ 9.5. This mark will be displayed with one decimal place, and is obtained as follow:

NF = [0.3 × NS + 0.2 × NC + 0.5 × NE]

Whenever applicable and if needed, the lecturer or head of discipline may require an oral evaluation which may replace one of the evaluation criteria above.

Subject matter

1.       TOF - Time-of-flight mass spectrometry;

Development of a TOF mass spectrometer (acceleration voltageseracao and beam collimation, mass callibration, ...)

Mass resolution, spatial and temporal distribution, kinetic energy release distribution;

Anion and cation production and detection;

Secondary beams production (e.g.. effusive beams, heating ovens);

Instrumentation (pulse generators, syncronous signal aquisition systems).

2.      Charge transfer in atom-molecule collision experiments (relvant to atmospheric, industrial and biological molecules);

Hyperthermal neutral potassium beam production (alkali atoms);

Neutral secondary species production (e.g. Langmuir-Taylor detector);

Dispersion and functional dependence of neutral beams;

Secondary beams preparation (e.g. effusive beams, heating ovens);

Development of relevant instrumentation.

3.       Dissociative Electron Attachment Processes in molecules (relvant to atmospheric, industrial and biological molecules);

Low-energy electron beam production (~ 70 meV);

Throcoidal electron monochromator with external magnetic field;

Production and collimation of low-energy electron beams (e.g. Faraday cups);

Secondary beam production (e.g.. effusive beams, heating ovens);

Development of proper instrumentation.

4.       Molecular clusters: formation and detection ;

Techniques for molecular cluster formation;

Helium nanodropletsin dissociative electron attachment processes;

Mass spectrometry in molecular clusters;

Applications;

5.       Electron transfer processes in anion H-, O-, OH- collisions with molecules (relvant to atmospheric, industrial and biological molecules);

production of anionic beams at intermediate and high energies;

Detection of anionic beams (e.g.. deflecting plates);

Wien filter;

Secondary beam production (e.g.. effusive beams, heating ovens);

Development of proper instrumentation.

6. Electron energy loss spectroscopy

Electron energy loss spectroscopy experimental set-up

Characterization of electron energy loss spectra

Elastic and inelastic differencial cross sections;

Absolute differencial cross section determination; 

7. Proton Transfer Mass Spectrometry PTR-MS

Fundamentals on proton transfer reaction;

Experimental concepts in PTR-MS;

Limitations of PTR-MS technique;

Applications;

Programs

Programs where the course is taught: