Spurious radiated power signal following massive material injections in JET and the effect of neutral gas pressure on resistive bolometers.

Massive material injections in the JET tokamak have been observed to substantially affect resistive bolometer measurements, resulting in a spurious radiated power signal proportional to the quantity injected and reaching up to 8 MW. These bolometers are calibrated and designed to operate in near vacuum but certain scenarios requiring large gas injections can push the neutral pressure past nominal values. This study demonstrates that the bolometry measurement can be affected at neutral pressures above 0.

Determination of 2D poloidal maps of the intrinsic W density for transport studies in JET-ILW.

The experimental method developed at ASDEX Upgrade for the determination of the intrinsic tungsten (W) density profile coupling data from the soft X-ray (SXR) diagnostic and vacuum-ultra-violet (VUV) spectroscopy has been upgraded for application to JET plasmas. The strong poloidal asymmetries in the SXR emission are modeled assuming a distribution, where is the flux coordinate, is the major radius, and is the fit parameter. The W density is calculated from the resulting 2D SXR emissivity maps accounting for contributions from a low-Z impurity (typically beryllium) and main ion with the assumption that their contributions are poloidally symmetric.

Carbon charge exchange analysis in the ITER-like wall environment.

Charge exchange spectroscopy has long been a key diagnostic tool for fusion plasmas and is well developed in devices with Carbon Plasma-Facing Components. Operation with the ITER-like wall at JET has resulted in changes to the spectrum in the region of the Carbon charge exchange line at 529.06 nm and demonstrates the need to revise the core charge exchange analysis for this line.

ITER-relevant calibration technique for soft x-ray spectrometer.

The ITER-oriented JET research program brings new requirements for the low-Z impurity monitoring, in particular for the Be—the future main wall component of JET and ITER. Monitoring based on Bragg spectroscopy requires an absolute sensitivity calibration, which is challenging for large tokamaks. This paper describes both “component-by-component” and “continua” calibration methods used for the Be IV channel (75.

A randomized, controlled trial of a brief interventional package for schizophrenic out-patients.

Objective: To evaluate the impact on outcome of a simple educational intervention in schizophrenic patients at risk of relapse.

Method: At discharge, 114 schizophrenic patients with at least one previous episode were assigned randomly to a simple educational intervention which had no resource implications, or standard care.

Results: The intervention failed to improve outcome.