A calorimeter is an object used for calorimetry, or the process of measuring the heat of chemical reactions or physical changes as well as heat capacity.
The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume.
Particle physics (also high energy physics) is the branch of physics that studies the nature of the particles that constitute matter and radiation.
In physics, the radiation length is a characteristic of a material, related to the energy loss of high energy, electromagnetic-interacting particles with it.
In optics, the refractive index or index of refraction of a material is a dimensionless number that describes how light propagates through that medium.
A scintillator is a material that exhibits scintillation—the property of luminescence, when excited by ionizing radiation.