Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

Continuous Electrocorticogram Epileptiform Discharges Due To Brain Gliosis

Cortical dysplasia is known to produce continuous epileptiform discharges (CEDs) on electrocorticogram (EcoG) and EEG recordings. The authors studied the incidence of CEDs on ECoGs and correlated this data with pathologic findings. Thirty ECoGs were reviewed that were performed on patients with parietal or occipital lobe epilepsy operated on since 1960. CED was classified as: (1) continuous or semicontinuous rhythmic spikes or sharp waves at frequencies ranging from 2 to 8 Hz, and (2) repetitive bursts of rhythmic polyspike activity lasting 2 to 10 s. All nontumoral pathologic specimens were reviewed. Epileptiform activity was classified using the following criteria: focal (one gyrus), regional (two gyri), lobar (three gyri), bilobar, or multilobar. Pathologic examination showed gliosis in eight specimens, focal cortical dysplasia in five specimens, tumoral lesions in eight specimens, and other pathology in nine specimens. CED was found in 11 ECoGs. In seven pathology specimens, significant gliosis was shown, and in the remaining four specimens, a dysplastic lesion was diagnosed. Epileptiform activity was widespread (lobar, bilobar, or multilobar) when gliosis or focal cortical dysplasia was present. Absence of epileptiform activity or a focal/regional distribution was found in tumors and other lesions. These data suggest that extensive gliotic lesions are highly epileptogenic and produce CEDs, which are morphologically undistinguishable from those produced by focal cortical dysplasia.204239242Dubeau, F., Palmini, A., Fish, D., Avoli, M., Gambardella, A., Spreafico, R., Andermann, F., The significance of electrocorticographic findings in focal cortical dysplasia: A review of their clinical, electrophysiological and neurochemical characteristics (1998) Electroencephalogr Clin Neurophysiol, 48 (SUPPL.), pp. 77-96Gambardella, A., Palmini, A., Andermann, F., Dubeau, F., DaCosta, J.C., Quesney, L.F., Andermann, E., Olivier, A., Usefulness of focal rhythmic discharges on scalp EEG of patients with focal cortical dysplasia and intractable epilepsy (1996) Electroencephalogr Clin Neurophysiol, 98, pp. 243-249Gloor, P., Contributions of electroencephalography and electrocorticography to the neurosurgical treatment of the epilepsies (1975) Neurosurgical Management of the Epilepsies, pp. 59-68. , Purpura D, Penry J, Walter R, eds. New York: Raven PressJasper, H., Electrocorticograms in man (1949) Electroencephalogr Clin Neurophysiol, 2, pp. 16-29Otsubo, H., Chitoku, S., Ochi, A., Jay, V., Rutka, J.T., Smith, M.L., Elliott, I.M., Snead O.C. III, Malignant rolandic-sylvian epilepsy in children: Diagnosis, treatment, and outcomes (2001) Neurology, 57, pp. 590-596Paglioti-Neto, E., Palmini, A., Costa, J.C., Histopathological pattern and putative pathogenetic mechanisms determine the degree of epileptogenicity in localized cortical dysplastic lesions (1996) Epilepsia, 37 (SUPPL. 5), p. 142Palmini, A., Gambardella, A., Andermann, F., Intrinsic epileptogenicity of human dysplastic cortex as suggested by corticography and surgical results (1995) Ann Neurol, 37, pp. 476-487Palmini, A., Gambardella, A., Andermann, F., Olivier, A., Da Costa, J.C., Tampieri, D., Robitaille, Y., Coutinho, L., Outcome of surgical treatment in patients with localized cortical dysplasia and intractable epilepsy (1996) Dysplasias of Cerebral Cortex and Epilepsy, pp. 367-374. , Guerrini R, Andermann F, Canapicchi R, Roger J, Zifkin BG, Pfanner P, eds. Philadelphia: Lippincott-RavenQuesney, L.F., Niedermeyer, E., Electrocorticography (1999) Electroencephalography: Basic Principles, Clinical Applications, and Related Fields. 4th Ed., pp. 741-747. , Niedermeyer E, Lopes da Silva F, eds. Philadelphia: Lippincott Williams & WilkinsRasmussen, T., Characteristics of a pure culture of frontal lobe epilepsy (1983) Epilepsia, 24, pp. 482-493Robain, O., Introduction to the pathology of cerebral cortical dysplasia (1996) Dysplasias of Cerebral Cortex and Epilepsy, pp. 1-9. , Guerrini R, Andermann F, Canapicchi R, Roger J, Zitkin BG, Pfanner P, eds. Philadelphia: Lippincott-RavenRobitaille, Y., Rasmussen, T., Dubeau, F., Histopathology of nonneoplastic lesions in frontal lobe epilepsy (1992) Frontal Lobe Seizures and Epilepsies: Advances in Neurology, 57, pp. 499-507. , Chauvel P, Delgado-Escueta AV, eds. New York: Raven PressTaylor, D.C., Falconer, M.A., Bruton, C.J., Corsellis, J.A.N., Focal dysplasia of the cerebral cortex in epilepsy (1971) J Neurol Neurosurg Psychiatr, 34, pp. 369-38

Early and continuing effects of combined alpha and beta irradiation of the lung:

This report summarizes an inhalation exposure experiment that concerns early and continuing effects of combined alpha and beta irradiation of the lung of rats. Both morbidity at 18 months and mortality within 18 months after exposure were examined for rats exposed to the beta-emitter /sup 147/Pm, the alpha-emitter /sup 238/Pu, or both combined. The results were used to validate hazard-function models that were developed (1)for pulmonary functional morbidity at 18 months and (2) for lethality from radiation pneumonitis and pulmonary fibrosis within 18 months. Both models were found to adequately predict the experimental observations after combined chronic alpha and beta irradiation of the lung. A relative biological effectiveness of approximately 7 was obtained for /sup 238/Pu alpha radiation compared to /sup 147/Pm beta radiation for both pulmonary functional morbidity and lethality from radiation pneumonitis and pulmonary fibrosis. 12 refs., 16 figs., 11 tabs