SPONTANEOUS OPTICAL FLASHES IN PROTON-IRRADIATED SOLID DEUTERIUM

Samples of solid deuterium, cooled below 4.2 K, and irradiated by 15 M eV protons, will spontaneously flash. The flash-spectrum occurs in the near infrared with a maximum close to 920 nm. The flash intensity is two to three orders of magnitude greater than a steady-state emission observed in the same spectral region. The flash frequency is 1 every 1 to 3 min after several hours of irradiation of 10 nA/cm2. Heat pulses have been detected accompanying many of the flashes and both can be s timulated by the application of external heat triggers. Following the optical flash, the steady-state emission intensity decreases by an amo unt that is wavelength dependent. While it is thought that these flash es are caused by atomic association in the solid, the species responsi ble for the optical emission is uncertain as is the transition itself.