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

Алгоритм динамического наблюдения пациентов с колоректальным раком в процессе комбинированного лечения

A large number of colon cancer cases are registered in Russia annually. Liver metastases are detected in half of them. Surgical treatment in combination with chemotherapy is the only effective method of treatment for such patients. Currently, 5- and 10-year life expectancy after such treatment varies within 24-58% and 17-25%, respectively. In the article, two cases demonstrate the possibilities of modern methods of combined treatment and observation of patients suffering from advanced stages of colon cancer. The protocol for case follow-up of these patients, applied in the clinic, is given. The application of this protocol makes it possible to identify new metastatic neoplasms in the liver at an early stage, which makes treatment less complicated. When interpreting the results of18F-FDG PET/CT, it is necessary to take into account that systemic chemotherapy suppresses the metabolic activity of the cells in metastatic focus. Given this, the appearance of new,18F-FDG PET/CT negative foci makes it justified to apply more active surgical tactics.Ежегодно в России регистрируется большое количество случаев рака толстой кишки, в половине из которых выявляются метастазы в печень. Хирургическое лечение в сочетании с химиотерапией является единственным эффективным методом лечения таких пациентов. В настоящее время 5- и 10-летняя продолжительность жизни после такого лечения находится в пределах 24-58 % и 17- 25 % соответственно. В статье на примере двух случаев демонстрируются возможности современных методов комбинированного лечения и наблюдения пациентов, страдающих раком толстой кишки в далеко зашедших стадиях. Приведен протокол динамического наблюдения этих больных, применяемый в клинике. Применение этого протокола позволяет выявлять появляющиеся новые метастатические образования в печени на ранней стадии, что делает их лечение менее сложным. При трактовке результатов ПЭТ КТ с 18F-ФДГ необходимо учитывать факт применения системной химиотерапии, которая подавляет метаболическую активность клеток метастатического очага. Учитывая это, появление в печени новых, негативных при ПЭТ КТ с 18F-ФДГ, очаговых образований делает оправданным применение по отношению к ним более активной хирургической тактики

Impact of nitrogen seeding on confinement and power load control of a high-triangularity JET ELMy H-mode plasma with a metal wall

This paper reports the impact on confinement and power load of the high-shape 2.5MA ELMy H-mode scenario at JET of a change from an all carbon plasma facing components to an all metal wall. In preparation to this change, systematic studies of power load reduction and impact on confinement as a result of fuelling in combination with nitrogen seeding were carried out in JET-C and are compared to their counterpart in JET with a metallic wall. An unexpected and significant change is reported on the decrease of the pedestal confinement but is partially recovered with the injection of nitrogen.Comment: 30 pages, 16 figure

Study of fast-ion transport induced by fishbones on JET

The impact of fishbone oscillations onto a confined fast-ion population is simulated for a JET plasma and benchmarked against experiment quantitatively with the help of neutron rate measurements. The transient drops in volume integrated neutron emission are found to be mainly caused by the spatial redistribution of the (neutral beam injected) fast-ion population confined in the plasma rather than by fast-ion loss. The simulations yield a quadratic dependence of the neutron drop on the fishbone amplitude. It is found that the simulations are able to correctly reproduce the magnitude of the experimentally observed drop in volume integrated neutron emission to within a factor 2. Furthermore, frequency chirping is found to be important. Omitting the fishbone frequency chirp in the simulations reduces the magnitude of the neutron rate drop (and hence fast-ion redistribution) to about half its original value