Liquid argon is advantageous as a sensitive medium for several reasons. The fact that argon is a noble element and therefore has a vanishing electronegativity means that electrons produced by ionizing radiation will not be absorbed as they drift toward the detector readout. Argon also scintillates when an energetic charged particle passes by, releasing a number of scintillation photons that is proportional to the energy deposited in the argon by the passing particle. Liquid argon is also relatively inexpensive, making large-scale projects economically feasible. However, one of the primary motivations for using liquid argon as a sensitive medium is its density. Liquid argon is around one thousand times denser than the gas used in Nygren's TPC design, which increases the likelihood of a particle interacting in a detector by a factor of around one thousand. This feature is particularly useful in neutrino physics, where neutrino–nucleon interaction cross sections are small.