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Nitrogen is a liquid under −195.8 °C (77.3 K).. In physics, cryogenics is the production and behaviour of materials at very low temperatures.. The 13th International Institute of Refrigeration's (IIR) International Congress of Refrigeration (held in Washington, DC in 1971) endorsed a universal definition of "cryogenics" and "cryogenic" by accepting a threshold of 120 K (−153 °C) to ...
Because of the extremely low temperatures, diagnosing the chemical status is a major issue when studying low temperature physics and chemistry. [ clarification needed ] The primary techniques in use today are optical - many types of spectroscopy are available, but these require special apparatus with vacuum windows that provide room temperature ...
For example, if the change is an increase in temperature at constant volume, with no phase change and no chemical change, then the temperature of the body rises and its pressure increases. The quantity of heat transferred, Δ Q , divided by the observed temperature change, Δ T , is the body's heat capacity at constant volume:
The following is a timeline of low-temperature technology and cryogenic technology (refrigeration down to close to absolute zero, i.e. –273.15 °C, −459.67 °F or 0 K). [1] It also lists important milestones in thermometry , thermodynamics , statistical physics and calorimetry , that were crucial in development of low temperature systems.
Einstein proposed that cooling bosonic atoms to a very low temperature would cause them to fall (or "condense") into the lowest accessible quantum state, resulting in a new form of matter. Bosons include the photon , polaritons , magnons , some atoms and molecules (depending on the number of nucleons , see #Isotopes ) such as atomic hydrogen ...
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation.
As the temperature is increased on such a system, particles move into higher and higher energy states, so that the number of particles in the lower energy states and in the higher energy states approaches equality. [10] (This is a consequence of the definition of temperature in statistical mechanics for systems with limited states.) By ...
For example, excited Cesium (Cs) vapors in thermionic converters form clusters of Cs-Rydberg matter which yield a decrease of collector emitting work function from 1.5 eV to 1.0–0.7 eV. Due to long-lived nature of Rydberg matter this low work function remains low which essentially increases the low-temperature converter's efficiency. [37]