Scintillation

About: Scintillation is a research topic. Over the lifetime, 14022 publications have been published within this topic receiving 187694 citations.

Rapid variability of extragalactic radio sources

Abstract: Thirty-one extragalactic radio sources have been observed at 2-4 hr intervals for 3-4 days at each of three epochs. The 15 compact sources in the sample appear to display two types of variability. One is probably weak flickering caused by refractive interstellar scintillation. The other is a larger amplitude variability, which is characterized by a narrow range of timescales of about 1-2 days. Three possible causes of the second type are discussed: (1) intrinsic variability; (2) scintillation from a very narrow disk component of the ISM; and (3) scintillation from clouds associated with a particular region of the ISM. It is suggested that the latter is the more likely explanation. 24 references.

Response of TAPS to monochromatic photons with energies between 45 and 790 MeV

Abstract: The Two Arm Photon Spectrometer TAPS - comprising 384 plastic-BaF2 scintillator telescopes - was tested with monochromatic photons in the energy range between 45 and 790 MeV. The energy resolution for a collimated photon beam hitting the central detector module was determined to sigma/E = 0.59% X E(gamma)-1/2 + 1.9% (E, given in GeV). For the the fast scintillation component alone sigma/E = 0.79% X E(gamma)-1/2 + 1.8% has been measured. The position resolution of the point of impact amounts to DELTAx = 2 cm (FWHM) at the highest energies which corresponds to 30% of the diameter of an individual module. Monte Carlo simulations using the code GEANT3 are in good agreement with the experimental results.

Scintillating double-beta-decay bolometers

Abstract: We present the results obtained in the development of scintillating double-beta-decay bolometers. Several Mo and Cd based crystals were tested with the bolometric technique. The scintillation light was measured through a second independent bolometer. A 140-g CdWO4 crystal was run in a 417-h live time measurement. Thanks to the scintillation light, the α background is easily discriminated, resulting in zero counts above the 2615-keV γ line of 208Tl. These results, combined with an extreme easy light detector operation, represent the first tangible proof demonstrating the feasibility of this kind of technique.

Scintillation characteristics of pure and Tl-doped CsI crystals

Abstract: The scintillation characteristics of pure and Tl-doped CsI were investigated. The scintillation light was detected with photomultipliers and silicon photodiodes. The influence of the Tl concentration on the light yield and on the decay times was studied upon excitation with gamma -rays and alpha -particles. The origin of the different emission components is discussed. >

GPS TEC and scintillation measurements from the polar ionosphere during the October 2003 storm

Abstract: [1] Severe ionospheric storms occurred at the end of October 2003. During the evening of 30 October a narrow stream of high electron concentration plasma crossed the polar cap in the antisunward ionospheric convection. A GPS scintillation receiver in the European high arctic, operating at 1.575 GHz, experienced both phase and amplitude scintillation on several satellite-to-ground links during this period. Close examination of the GPS signals revealed the scintillation to be co-located with strong gradients in Total Electron Content (TEC) at the edge of the plasma stream. The gradient-drift instability is a likely mechanism for the generation of the irregularities causing some of the scintillation at L band frequencies during this storm. The origin of the high TEC is explored and the possible implications of the work for scintillation forecasting are noted. The results indicate that the GPS scintillation over Svalbard can originate from traceable ionospheric plasma structures convecting from the American sector.