Specific devices for calorimetric measurements in high-energy physics. At very high energies, magnetic measurements become expensive because they require very strong magnetic fields or very long detection arms to measure small trajectory changes. Magnetic detection cannot be used for measurement of energies of neutral particles (neutrons or photons). Calorimetric measurement measures the total energy that was realized in some detection medium. A calorimeter absorbs the full kinetic energy of a particle and produces a signal that is proportional to the absorbed energy. The system of deposition of energy depends on the kind of detected particles. High energy photons deposit energy when they transform into electron-positron pairs. Produced electrons and positrons deposit their energy by ionizing atoms. When they are very energetic, they lose most of their energy through bremsstrahlung. These bremsstrahlung photons can again be converted into electron-positron pairs. Hadrons lose most of their energy through successive nuclear collisions. In most materials with Z > 10, the mean free path for nuclear collision is greater than the free path for electromagnetic interactions; because of that, calorimeters for measurement of deposited electromagnetic energy are thinner than calorimeters for measurement of energy deposited by hadrons. Interaction probabilities for neutrons are small, and they can escape undetected. This reduces accuracy in measurement. Calorimeters can function as ionizing chambers (liquid-argon calorimeters) through production of scintillation light or scintillation-sensitive detectors (NaI), or they can relay on the production of Cernikov light (lead glasses). They can be constructed as homogeneous media or sampling calorimeters. Sampling calorimeters mainly use absorber material that is interspersed with active sampling devices to detect realized energy. This kind of detector is easier and cheaper to build, but has worse resolution than homogeneous detectors.