The response of several luminescent materials to keV and MeV ions

In-situ luminescence monitoring of ion-induced damage evolution in SiO2 and Al2O3

“…For 2 MeV H irradiation, the intensity of the main emission bands is a factor two higher than for 3.5 MeV He ions. This result is in agreement with McCarthy et al [4] where the absolute efficiency of several luminescent materials was compared in terms of light yield (i.e., number of photons emitted per incident Additionally, the IBIL intensities from α-Al 2 O 3 samples were found to be several orders of magnitude higher than that of a-SiO 2 and quartz, in agreement with the present results. Fig.…”

“…Hence de-excitation from the color centers is a rate limiting process and saturation results. In our case the ratio between the luminescent efficiency for 3.5 MeV He and 2 MeV H ion irradiation is around 4.5 in agreement with McCarthy et al [4].…”

“…Luminescence provides information about the upper electronic levels of a material (near the Fermi level), particularly for intra-gap levels associated with impurities and defect centers, such as those introduced by irradiation. The luminescence induced by ion-beam irradiation, commonly named ionoluminescence or ion beam-induced luminescence (IBIL), is a technique capable of acquiring information about intrinsic or pre-existing defects in materials as well as in-situ information about the microscopic processes accompanying the generation of damage from energetic ions, their kinetic evolution with the accumulation with increasing ion fluence, the formation of color centers, and their recovery with thermal annealing [2][3][4][5][6][7][8][9][10][11][12][13][14]. The visible light produced during luminescence is a result of outer shell transitions.…”

Ionoluminescent response of several phosphor screens to keV ions of different masses

“…While operation up to 10 keV does not present any serious difficulties, extending the range up to 33 keV is a more delicate task, since these screens are bad conductors and are prone to produce arcs. 18 This is aggravated by the fact that for ion detection the phosphor layer cannot be coated with a very thin layer of aluminum ͑which is usually done to avoid charge accumulation on a phosphor surface for soft and hard x-ray detection͒, which is customarily connected to ground to suppress this space-charge effect. Here, this problem was overcome by placing a thin nickel grid, with a transparency of 80%, over the phosphor layer.…”

“…20 for disk sources which results in a fixed error of approximately 1% for absolute measurements. 18 Second, the photon fluxes reaching the photomultiplier were determined from the time integrated light signals using wavelength sensitivity curves provided by the manufacturer 19 after correcting for transmission losses in the vacuum window and for signal amplification ͑fixed at 1 V / A͒.…”