Search results for "IRRADIATION"
showing 10 items of 1012 documents
Neutron-induced soft errors in advanced Flash memories
2008
Atmospheric neutrons are a known source of Soft Errors (SE), in static and dynamic CMOS memories. This paper shows for the first time that atmospheric neutrons are able to induce SE in Flash memories as well. Detailed experimental results provide an explanation linking the Floating Gate (FG) cell SE rate to the physics of the neutron-matter interaction. The neutron sensitivity is expected to increase with the number of bits per cell and the reduction of the feature size, but the SE issue is within the limit of current ECC capabilities and will remain so in the foreseeable future.
SOFT X-RAY IRRADIATION OF PURE CARBON MONOXIDE INTERSTELLAR ICE ANALOGUES
2012
There is an increasing evidence for the existence of large organic molecules in the interstellar and circumstellar medium. Very few among such species are readily formed in conventional gas-phase chemistry under typical conditions of interstellar clouds. Attention has therefore focused on interstellar ices as a potential source of these relatively complex species. Laboratory experiments show that irradiation of interstellar ice analogues by fast particles or ultraviolet radiation can induce significant chemical complexity. However, stars are sources of intense X-rays at almost every stage of their formation and evolution. Such radiation may thus provide chemical changes in regions where ult…
Response-theory for nonresonant hole burning: Stochastic dynamics
2001
Using non-linear response theory the time signals relevant for nonresonant spectral hole burning are calculated. The step-reponse function following the application of a high amplitude ac field (pump) and an intermediate waiting period is shown to be the sum of the equilibrium integrated response and a modification due to the preparation via ac irradiation. Both components are calculated for a class of stochastic dipole reorientation models. The results indicate that the method can be used for a clearcut distinction of homogeneously and heterogeneously broadened susceptibilities as they occur in the relaxation of supercooled liquids or other disordered materials. This is because only in the…
In situobservation of the formation, diffusion, and reactions of hydrogenous species inF2-laser-irradiatedSiO2glass using a pump-and-probe technique
2006
We quantitatively studied the formation, diffusion, and reactions of mobile interstitial hydrogen atoms $({\mathrm{H}}^{0})$ and molecules $({\mathrm{H}}_{2})$ in ${\mathrm{F}}_{2}$-laser-irradiated silica $(\mathrm{Si}{\mathrm{O}}_{2})$ glass between 10 and $330\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. Two key techniques were used: single-pulse ${\mathrm{F}}_{2}$ laser photolysis of silanol (SiOH) groups to selectively create pairs of ${\mathrm{H}}^{0}$ and oxygen dangling bonds (nonbridging oxygen hole centers, NBOHC), and in situ photoluminescence measurements of NBOHCs to monitor their reactions with ${\mathrm{H}}^{0}$ and ${\mathrm{H}}_{2}$ as a function of time and temperature. A smalle…
Energy- and angle-resolved electron distribution in the photodetachment ofF−
2009
We report calculations of energy- and angle-resolved photoelectron distribution of ${\text{F}}^{\ensuremath{-}}$ irradiated by a linearly strong short infrared pulse, performed by evaluating the photoelectron ejection probability in the framework of a modified Keldysh theory, taking into account the temporal behavior of the pulse and the spatial inhomogeneity of the laser intensity. Results of the calculations are compared with the measurements of the photoelectron angular distribution recently appearing in the literature. The oscillations found in the experimental data are explained in terms of quantum interference effects.
Efficiency and dynamic range of the photostimulable x-ray storage material KBr:In
1997
By calibrating the photostimulated luminescence (PSL) response with the known intensity of a standard light source, efficiency of the KBr:In powder material to the x- ray bremsstrahlung exposure at room temperature is estimated. At 44 and 85 kV voltages on the x-ray tube, the values of (8 plus or minus 2) multiplied by 10 5 and (18 plus or minus 4) multiplied by 10 5 photons from 1 mm 2 area of the 1 mm thick material are obtained as PSL responses on a 1 mR x-ray exposure, respectively. Under an assumption of the uniform x-ray excitation within the material, the maximum values for the x-ray irradiation dose and the PSL response both corresponding to the upper limit of linearity range are te…
Study of the Planacon XP85012 photomultiplier characteristics for its use in a Cherenkov detector
2016
Main properties of the multi-anode microchannel plate photomultiplier to be used in a Cherenkov detector are discussed. The laboratory test results obtained using irradiation of the MCP-PMT photocathode by picosecond optical laser pulses with different intensities (from single photon regime to the PMT saturation conditions) are presented. peerReviewed
Defect recovery in aluminum irradiated with protons at 20 K.
1987
Aluminum single crystals have been irradiated with 7.0-MeV protons at 20 K. The irradiation damage and its recovery are studied with positron-lifetime spectroscopy between 20 and 500 K. Stage-I recovery is observed at 40 K. At 240 K, loss of freely migrating vacancies is observed. Hydrogen in vacancies is found to stabilize the vacancies and prolong stage III to above 280 K, where the hydrogen bound to vacancies is released. Single and multiple occupancy of hydrogen atoms at monovacancies is put forward as the reason for the two recovery stages between 280 and 400 K. A binding energy of 0.53 +- 0.03 eV is found for a hydrogen atom trapped at a monovacancy. The results are in excellent agree…
Detection of Interstitial Oxygen Molecules in SiO2Glass by a Direct Photoexcitation of the Infrared Luminescence of SingletO2
1996
The presence of interstitial oxygen molecules in glassy ${\mathrm{SiO}}_{2}$ has been demonstrated directly by 1064.1 nm $({\ensuremath{\nu}}^{\ensuremath{'}\ensuremath{'}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0)\ensuremath{\rightarrow}({\ensuremath{\nu}}^{\ensuremath{'}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1)$ excitation of the forbidden ${O}_{2}$ molecule $^{1}\ensuremath{\Delta}_{g}({\ensuremath{\nu}}^{\ensuremath{'}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0)\ensuremath{\rightarrow}^{3}\ensuremath{\Sigma}_{g}({\ensuremath{\nu}}^{\ensuremath{'}\ensuremath{'}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0)$ luminescence transition at 1272 nm in S…
Anomalous behavior of LiF:Mg,Cu,P (TLD100H) irradiated with electron beams
2006
Abstract Thermoluminescent dosimeters of LiF:Mg,Cu,P (TLD100H) were exposed to 60Co γ -ray, protons, high energy electrons and the glow curves were analyzed. We observed an unusual behavior of the TL response of dosimeters to 7 and 14 MeV electron beam. In fact the relative amplitude between two of the five peaks (2° and 3° peaks) assumes values smaller than the unity for doses up to 5 Gy and values greater than the unity for doses equal to or greater than 10 Gy. A possible explanation of this behavior is given adopting a model of the formation of the peaks 2° and 3° and examining the different ways of energy release in matter for each beam. To perform this analysis we deconvoluted the glow…