Although we do not yet know how long the social distancing related to the Covid-19 pandemic will last, and regardless of the changes that had to be made in the evaluation of the June 2020 session in relation to what is provided for in this learning unit description, new learnig unit evaluation methods may still be adopted by the teachers; details of these methods have been - or will be - communicated to the students by the teachers, as soon as possible.
We elaborate on the means to produce, store and guide charged particles using electric and magnetic fields. We illustrate the relevance of this know-how to the study of cross sections of collisions or photon-induced processes. An emphasis is then put on ultra-sensitive and precise techniques of spectroscopy using the detection of photons or of charged particles. Different cooling techniques, i.e. supersonic expansion and buffer gas cooling, are also presented to simplify and enhance quantized signatures in absorption or collision experiments.
At the end of this learning unit, the student is able to :
a. Contribution of the teaching unit to the learning outcomes of the programme (PHYS2M and PHYS2M1)
AA 1.1, AA 1.2, AA1.3, AA1.4, AA 1.5, AA1.6, AA2.1, AA2.2, AA 3.1, AA 4.2, AA5.1, AA5.2, AA 5.3,AA 6.1, AA 7.2, AA 7.3, AA7.5, AA8.1, AA 8.2
b. Specific learning outcomes of the teaching unit
At the end of this teaching unit, the student will be able to :
1. determine the most efficient experimental methodology to study a problem in atomic or molecular physics ;
2. know what are the limitations and advantages of various experimental techniques in atomic and molecular physics ;
3. identify the methods in use in scientific publications and evaluate their pertinence
4. put into equations the trajectory of charged particle beam and simulate it with appropriate software tools ;
5. identify and characterize the elements of a particle accelerator.
The contribution of this Teaching Unit to the development and command of the skills and learning outcomes of the programme(s) can be accessed at the end of this sheet, in the section entitled “Programmes/courses offering this Teaching Unit”.
1) Charged particle optics
- generation of charged particles: electron, positron, ion
- basic principles of charged particle optics : general equations of motion, paraxial approximation and applications to electric and magnetic fields
- concept of emittance: Liouville theorem and derivation of the beam envelope in phase space
- practical training with real beams and simulation tools
- velocity distributions : gas cell, effusive and supersonic beam
- velocity selection : rotating slit, Doppler, fast beam
- kinematics of beam-beam interaction : crossed beams, merged beams
- form factor : the animated beam method
- detection techniques : surface ionization, laser-induced fluorescence, electron multipliers, position sensitive detectors
- analysis methods : translational spectroscopy, coincidence detection, 3D imaging
- ion traps : Penning trap, Paul trap, quadrupole trap, electrostatic cavity
- storage rings : electron-ion interaction, sympathetic and stochastic cooling
- frequency modulation
- -principle of a lock-in amplifier
- cavity enhanced and cavity ringdown spectroscopy
- NICE-OHMS spectroscopy
- photofragmentation spectroscopy
- photoelectron spectroscopy
- spectroscopy in an ion-trap
Visits to a large European experimental facility will be organised.
High-resolution molecular spectroscopy, handbook, Wiley online library 2011.