Diagnostics development for quasi-steady-state operation of the Wendelstein 7-X stellarator (invited)

The critical issues in the development of diagnostics, which need to work robust and reliable under quasi-steady state conditions for the discharge durations of 30 min and which cannot be maintained throughout the one week duration of each operation phase of the Wendelstein 7-X stellarator, are being discussed.

Design criteria of the bolometer diagnostic for steady-state operation of the W7-X stellarator

A bolometric diagnostic system with features necessary for steady-state operation in the superconducting stellarator W7-X was designed. During a pulse length of 1800 s with an ECRH (electron cyclotron resonance heating) power of 10 MW, the components suffer not only from a large thermal load but also from stray radiation of the nonabsorbed isotropic microwaves. This paper gives an overview of the technical problems encountered during the design work and the solutions to individual problems to meet the special requirements in W7-X, e.g., component thermal protection, detector offset thermal drift suppression, as well as a microwave shielding technique.

Diagnostics design for steady-state operation of the Wendelstein 7-X stellarator

The status of the diagnostic developments for the quasistationary operable stellarator Wendelstein 7-X (maximum pulse length of 30 min at 10 MW ECRH heating at 140 GHz) will be reported on. Significant emphasis is being given to the issue of ECRH stray radiation shielding of in-vessel diagnostic components, which will be critical at high density operation requiring O2 and OXB heating.

The prevalence of undiagnosed metabolic abnormalities in people with serious mental illness

The prevalence of metabolic syndrome is increased 2-3-fold in people with serious mental illness (SMI). Monitoring of physical health in these individuals is poor, despite clear guidance from the National Institute of Health and Clinical Excellence. The aim of this study was to assess the proportion of people with SMI who had been screened for metabolic abnormalities within the previous year and in a further study to assess the prevalence of undiagnosed metabolic abnormalities in people who had not been screened. The notes and computer records of 100 patients with SMI from community and in-patient settings were evaluated. In a subsequent study, the prevalence of metabolic syndrome was assessed in 71 previously unscreened patients. The study was carried out at the psychiatric in-patient and out-patient units in Southampton and Winchester. The frequency of screening and prevalence of the metabolic syndrome as defined by the International Diabetes Federation (IDF) were assessed. There was documented evidence that the following cardiovascular risk factors had been measured in the previous year: blood pressure (32%), glucose (16%), lipids (9%) and weight (2%). In the metabolic abnormalities study, 41 of 71 (58%) patients were found to fulfil the IDF criteria for the metabolic syndrome. Two had previously undiagnosed diabetes. Twelve percent of patients had a greater than 20% risk of a cardiovascular event within the next 10 years. Despite clear guidance and a high prevalence of undiagnosed metabolic syndrome, screening rates for metabolic abnormalities in people with SMI remain low. Improved screening of metabolic complications should lead to better identification and treatment of this clinical problem.

Emergency service in an ambulatory outpatient women's health centre

In order to optimise the service for patients who require an emergency service, and to meet patient needs, we conducted a study in Shillo ambulatory outpatient women's health centre, affiliated to Rabin Medical Center and Tel Aviv University. The study population consisted of 512 women, aged 25 - 55 years, attending the centre for emergency consultation and urgent obstetrics and gynaecological day care. Before the doctor's visit and at the end of the session, the women were asked to complete a 20-item questionnaire survey. The most common complaints were related to pregnancy complications (29%). Significant improvement in their problems was reported by almost 70% of these women; 20% thought that the information they received was inadequate or unsatisfactory. Less than 10% were referred to the hospital for further care such as surgery. Most of the women (96%) reported that they would continue to use these emergency services in the future if needed. There was a statistically significant difference between the doctors' opinion and the nurse regarding the urgency and severity of the patients' problems. The nurses graded them lower than did the doctors. There was also a statistically significant difference between patients' opinion and the nurses and the doctors regarding the urgency and severity of the patients' problems. The patients graded the problems as more urgent and more severe than the nurses or doctors. We concluded that an ambulatory emergency service is an essential part of an ideal ambulatory womens' health centre but it requires substantial progress to meet the patients' needs.

Economic evaluation of fulvestrant as an extra step in the treatment sequence for ER-positive advanced breast cancer

Drug therapies for advanced breast cancer in hormone-receptor-positive disease include both hormonal and chemotherapies. Current UK practice is to minimise toxicity by using sequential hormonal agents for as long as clinically appropriate. A Markov model was developed to investigate the cost effectiveness of different sequences of therapies, particularly exploring the effects of adding an additional hormonal agent, fulvestrant, to the treatment pathway. A systematic review was undertaken and a panel of seven UK oncologists validated assumptions used for treatment efficacy, treatment pathways and resources used. Fulvestrant was found to be a cost-effective treatment option when added to the treatment sequence as a second- or third-line hormonal therapy for advanced disease. For a cohort of 1000 patients, fulvestrant as a second-line hormone therapy provided an additional 47 life years and 41 quality-adjusted life years (QALYs), at an additional cost of pound 301 359. This equated to pound 6500 per life years gained and pound 7500 per QALY. When used as a third-line option, the fulvestrant arm was dominant providing an increase in health benefit of 27 QALYs for the whole cohort, at a mean overall cost reduction of pound 430 per patient. Sensitivity analyses showed these results to be robust, demonstrating that fulvestrant is an economically viable additional endocrine option in the United Kingdom for the treatment of hormone responsive advanced breast cancer.

Diagnostic developments for quasicontinuous operation of the Wendelstein 7-X stellarator

The stellarator Wendelstein 7-X will allow for quasicontinuous operation with the duration only being limited to two 30 min discharges per day, at a continuous heating power of 10 MW electron cyclotron resonance heating (ECRH) at 140 GHz, by the capacity of the cooling water reservoir. This will result in high thermal loads on all plasma facing components of 50-100 kW/m(2) from radiation alone and of up to about 500 kW/m(2) on components additionally exposed to convective loads. In high density scenarios toroidally varying ECRH stray radiation levels of 50-200 kW/m(2) need to be coped with, requiring careful material selection and different shielding and hardening techniques. Furthermore, a gradual buildup of coatings on plasma facing optical components, which without any measures being taken, would lead to high transmission losses already within a few days of long pulse operation (equivalent to about 1 year of operation in pulsed devices like JET or ASDEX-upgrade) and therefore needs to be prevented as much as possible. In addition in situ cleaning as well as absolute calibration techniques need to be developed for all plasma facing optical systems. Here we report about some of our efforts to find, for various types of diagnostics, ways to cope with these adverse effects. Moreover, we give a few examples for individual diagnostic specific issues with respect to quasicontinuous operation, such as the development of a special integrator for the magnetic diagnostics as well as special interferometer types which can cope with unavoidable vibrations and slow path length changes due to, e.g., thermal expansion of the plasma vessel.

Bayesian experimental design of a multichannel interferometer for Wendelstein 7-X

Bayesian experimental design (BED) is a framework for the optimization of diagnostics basing on probability theory. In this work it is applied to the design of a multichannel interferometer at the Wendelstein 7-X stellarator experiment. BED offers the possibility to compare diverse designs quantitatively, which will be shown for beam-line designs resulting from different plasma configurations. The applicability of this method is discussed with respect to its computational effort.