Although we do not yet know how long the social distancing related to the Covid19 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 knowhow to the study of cross sections of collisions or photoninduced processes. An emphasis is then put on ultrasensitive 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 :  
1  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 beambeam interaction : crossed beams, merged beams
 form factor : the animated beam method
 detection techniques : surface ionization, laserinduced 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 : electronion interaction, sympathetic and stochastic cooling

Absorption spectroscopy
 frequency modulation
 principle of a lockin amplifier
 cavity enhanced and cavity ringdown spectroscopy
 NICEOHMS spectroscopy
 photofragmentation spectroscopy
 photoelectron spectroscopy
 spectroscopy in an iontrap
Visits to a large European experimental facility will be organised.
Highresolution molecular spectroscopy, handbook, Wiley online library 2011.