Experimental methods of vacuum and low temperatures for the experimental study of complex thermodynamic systems such as superfluid and superconductive systems.
The aim of the course is the acquisition of experimental knowledge and methodologies of vacuum and low temperatures through the experimental study of complex thermodynamic phenomena such as superfluidity and superconductivity, as well as devices of interest for technological applications, such as for example phase transition, superconducting junctions, bolometers, calorimeters, SQuIDs. The technology of vacuum and of the production of low temperatures and, even if less frequently, the technologies of low temperature devices are now of industrial interest in many realities in the Northwest / Tuscan basin (Thales Alenia Space (Mi), Kaiser Italy (Li), Simic (Cn), Rial Vacuum (Pr), Pasquali Microwave System (Fi), ASG (Ge), Columbus (Ge), Agilent Technologies (To), CGS (Mi)). The course is aimed at both those who have interests in fundamental science and those who want to acquire professional knowledge to better integrate into the industrial reality.
Acquisition of advanced experimental knowledge and methodologies of thermodynamics applied at low temperatures and to the detection of radiation, thermal sensors and associated electronics.
Lectures in the classroom and 6 afternoon experiences in the teaching laboratory of low temperatures. Arguments of Experiences. 1-Cooling with LHe and Thermometry. 2-Thermal conductivity and measurement of the thermal input of a cryostat 3-Fluid-superfluid lambda transition 4-Eccitazionimeccaniche in the superfluid: second type sound wave. 5-Transition from normal to superconductive conduction 6- Measure of a device: Superconducting-Isolating-Superconductor tunnel junction (within the limits of availability of the devices themselves, the use of a different device can be agreed with the students).
Topics of the course. 1. Vacuum: fluid and dry sealed primary pumps, turbomolecular, fluid, getter and ionic pumps, vacuum measurement with mechanical, thermal, ionic cathodic hot and cold transducers. 2. Cryogenics: Stirling and Gifford Mac Mahon cycles, pulsed tubes, gas liquefaction and Joule Thompson expansion, liquefying agents for nitrogen and helium, magnetic refrigeration, dilution chillers. Temperature measurements: absolute temperature and standard scale up to mK, primary and secondary thermometers. 3. Physics of some low temperature systems: electrical and thermal conduction, superfluidity and lambda transition, HeI and HeII and London model, thermomechanical effects, superconductivity and its experimental evidences, classification in superconductors of type I and II, elements of the theory microscopic BCS and forbidden gap, thermodynamics of the superconductor and elements of the Ginzburg Landau theory. 4. Physics of some low-temperature devices, one or two selected between: superconducting junctions (SIS), quantum interference device (SQUID), quantum dots (QDot) and single electron transistors (SET), bolometers and superconducting calorimeters (TES) .
FLAVIO GATTI (President)
DANIELE MARRE'
MARIO AGOSTINO ROCCA
Interview on the arguments of the course, or, execution of a laboratory experience with presentation of the result.
Verification of the knowledge acquired in the interview or, in the presentation of the results of the laboratory experience.
