What is the impact of a pre-hospital geriatrician led telephone 'Silver Triage' for older people living with frailty?

PURPOSE

Most older people are conveyed to hospital via ambulance, therefore presenting a focus to reduce hospitalisation. North Central London has introduced 'Silver Triage', a pre-hospital telephone support scheme where geriatricians support the London Ambulance Service with clinical decision-making.

METHODS

Data from the first 14 months was analysed descriptively.

RESULTS

There have been 452 Silver Triage cases (November 2021 to January 2023). 80% resulted in a decision to not convey. The mode clinical frailty scale (CFS) was 6. CFS did not influence conveyance rates. Prior to triage, paramedics thought hospitalisation was not required in 44% of cases (n = 72/165). All paramedics surveyed (n = 176) would use the service again. Most (66%, n = 108/164) felt they learnt something and 16% (n = 27/164) reported it changed their decision-making process.

CONCLUSION

Silver Triage has the potential to improve the care of older people by preventing unnecessary hospitalisation and has been well received by paramedics.

Improving domestic violence screening practices in the emergency department: an Australian perspective

INTRODUCTION

Domestic violence (DV) is a major cause of morbidity worldwide. The ED is a location recommended for opportunistic screening. However, screening within EDs remains irregular.

OBJECTIVE

To examine intrinsic and extrinsic barriers to routine screening in Australian EDs, while describing actions taken after identification of DV.

METHODS

Emergency clinicians at nine public hospitals participated in an anonymous online survey. Factor analysis was performed to identify principal components around attitudes and beliefs towards screening.

RESULTS

In total, 496 emergency clinicians participated. Universal screening was uncommon; less than 2% of respondents reported screening all adults or all women. Although willing, nearly half (45%) reported not knowing how to screen. High patient load and no single rooms were 'very or severely limiting' for 88% of respondents, respectively, while 24/7 social work and interpreter services, and online/written DV protocols were top enablers. Factor analysis identified four distinct intrinsic belief components: (1) screening is not futile and could be done in ED, (2) screening will not cause harm, (3) there is a duty to screen and (4) I am willing to screen.

CONCLUSION

This study describes a culture of Queensland ED clinicians that believe DV screening in ED is important and interventions are effective. Most ED clinicians are willing to screen. In this setting, availability of social work and interpreter services are important mitigating resources. Clinician education focusing on duty to screen, coupled with a built-in screening tool, and e-links to a local management protocol may improve the uptake of screening and subsequently increase detection.

Providing care for older adults in the Emergency Department: expert clinical recommendations from the European Task Force on Geriatric Emergency Medicine

Aim

The aim was to develop expert clinical recommendations on Geriatric Emergency Medicine to be disseminated across Europe.

Findings

Eight posters with expert clinical guidelines on the most important topics in Geriatric Emergency Medicine are now available through https://posters.geriemeurope.eu/.

Message

Expert clinical recommendations for Geriatric Emergency Medicine in Europe were created and are ready for dissemination across Europe.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00578-1.

Purpose

Despite the rapidly expanding knowledge in the field of Geriatric Emergency Medicine in Europe, widespread implementation of change is still lacking. Many opportunities in everyday clinical care are missed to improve care for this susceptible and growing patient group. The aim was to develop expert clinical recommendations on Geriatric Emergency Medicine to be disseminated across Europe.

Methods

A group of multi-disciplinary experts in the field of Geriatric Emergency Medicine in Europe was assembled. Using a modified Delphi procedure, a prioritized list of topics related to Geriatric Emergency Medicine was created. Next, a multi-disciplinary group of nurses, geriatricians and emergency physicians performed a review of recent guidelines and literature to create recommendations. These recommendations were voted upon by a group of experts and placed on visually attractive posters. The expert group identified the following eight subject areas to develop expert recommendations on: Comprehensive Geriatric Assessment in the Emergency Department (ED), age/frailty adjusted risk stratification, delirium and cognitive impairment, medication reviews in the ED for older adults, family involvement, ED environment, silver trauma, end of life care in the acute setting.

Results

Eight posters with expert clinical recommendations on the most important topics in Geriatric Emergency Medicine are now available through https://posters.geriemeurope.eu/.

Conclusion

Expert clinical recommendations for Geriatric Emergency Medicine may help to improve care for older patients in the Emergency Department and are ready for dissemination across Europe.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00578-1.

Mortality risk for different presenting complaints amongst older patients assessed with the Manchester triage system

PURPOSE

Older people often present to the Emergency Department with nonspecific complaints. We aimed (1) to examine characteristics of older patients presenting to the ED triaged with the presentational flowchart 'unwell adult' of the Manchester triage system (MTS) and (2) to assess the different mortality and admission rates among triage categories.

METHODS

Retrospective cohort study including all consecutive patients aged 70 years and older who visited the ED of a tertiary care hospital in the Netherlands during a 1-year period. The primary outcome was 30-day mortality. Secondary outcomes were 7-day mortality, hospital admission and ED length of stay.

RESULTS

4255 patients were included in this study. Mean age was 78 years (IQR 73.9-83.4) and 2098 were male (49.3%). The MTS presentational flowchart 'unwell adult' was the most commonly used flowchart (n = 815, 19.3%). After the infrequent flowchart 'major trauma' (n = 9, 13.8%), 'unwell adult' had the highest 30-day mortality (n = 88, 10.8%). When compared to all other flowcharts, patients assigned as 'unwell adult' have significantly higher 30-day mortality rates (OR 1.89 (95%CI 1.46-2.46), p =  < 0.001), also when adjusted for age, gender and triage priority (OR 1.75 (95%CI 1.32-2.31), p =  < 0.001). Patients from the 'unwell adult' flowchart had the highest hospital admission rate (n = 540, 66.3%), and had among the longest ED length of stay.

CONCLUSIONS

Older ED patients are most commonly assigned the presentational flowchart 'unwell adult' when using the MTS. Patients in this category have the highest non-trauma mortality and highest hospital admission rates when compared to other presenting complaints.

Forward modeling of pile-up events in liquid scintillator detectors for neutron emission spectroscopy

When using liquid scintillator detectors to measure the neutron emission spectrum from fusion plasmas, the problem of pile-up distortion can be significant. Because of the large neutron rates encountered in many fusion experiments, some pile-up distortion can remain even after applying traditional pile-up elimination methods, which alters the shape of the measured light-yield spectrum and influences the spectroscopic analysis. Particularly, pile-up events appear as a high-energy tail in the measured light-yield spectrum, which obfuscates the contribution that supra-thermal ions make to the energy spectrum. It is important to understand the behavior of such "fast ions" in fusion plasmas, and it is hence desirable to be able to measure their contribution to the neutron spectrum as accurately as possible. This paper presents a technique for incorporating distortion from undetected pile-up events into the analysis of the light-yield spectrum, hence compensating for pile-up distortion. The spectral contribution from undetected pile-up events is determined using Monte Carlo methods and is included in the spectroscopic study as a pile-up component. The method is applied to data from an NE213 scintillator detector at JET and validated by comparing with results from the time-of-flight spectrometer TOFOR, which is not susceptible to pile-up distortion. Based on the results, we conclude that the suggested analysis method helps counteract the problem of pile-up effects and improves the possibilities for extracting accurate fast-ion information from the light-yield spectrum.

548 FRAILTY ANALYSIS ACROSS POPULATIONS: THE USE OF THE HOSPITAL FRAILTY RISK SCORE IN SPECIALISED SERVICES USING NHS NATIONAL DATA

Introduction

Frailty is increasingly used to risk stratify older people, but across specialised services there is no standardised approach. The aim of this study was to answer the question posed by NHS England to assess frailty could be measured and related to outcomes across Specialsed Services. The Hospital Frailty Risk Score (HFRS) was used and the data published in Age and Ageing in 2020.

Method

A retrospective cohort study was performed using the Secondary Uses Service (SUS) electronic database for people aged 75 or older admitted between April 2017 and March 2018. Based on HFRS, the populations were risk stratified into mild, moderate and severe frailty risk. The relationships with length of stay, readmission rate, mortality and some selected condition specific treatment complications were quantified using descriptive statistics.

Results

Frailty was differentially distributed across the specialties; around one-third had mild frailty; another third had moderate frailty and one-quarter severe frailty. Increasing frailty risk was associated with increased length of stay for the index admission, more days in hospital in the year following intervention and increased risk of dying in hospital. Severe frailty was a powerful discriminator of the risk of death; between 25 and 40% of those with severe frailty risk died at 30 months across all specialties.

Conclusions

This study demonstrates the first application of the HFRS to a national dataset to describe service outcomes and mortality for older people undergoing a range of specialised interventions. This information was used to identify those that might benefit from holistic assessment, aid prognostication, commissioning and service planning. It informed the promotion of quality improvement work in this area via the Specialised Clinical Frailty Network. By implementing the HFRS, changes in outcomes can be plotted across years to assess improvements, performance and benchmarking.

New method for time alignment and time calibration of the TOFOR time-of-flight neutron spectrometer at JET

The TOFOR time-of-flight (TOF) neutron spectrometer at the Joint European Torus (JET) is composed of 5 start (S1) and 32 stop (S2) scintillation detectors. Recently, the data acquisition system (DAQ) of TOFOR was upgraded to equip each of the 37 detectors with its own waveform digitizer to allow for correlated time and pulse height analysis of the acquired data. Due to varying cable lengths and different pulse processing pathways in the new DAQ system, the 160 (5 · 32) different TOF pairs of start-stop detectors must be time-aligned to enable the proper construction of a summed TOF spectrum. Given the time (energy) resolution required by the entire spectrometer system to measure different plasma neutron emission components, it is of importance to align the detector pairs to each other with sub-nanosecond precision. Previously, the alignment partially depended on using fusion neutron data from Ohmic heating phases of JET experimental pulses. The dependence on fusion neutron data in the time alignment process is, however, unsatisfactory as it involves data one would wish to include in an independent analysis for physics results. In this work, we describe a method of time-aligning the detector pairs by using gamma rays. Given the known geometry and response of TOFOR to gamma rays, the time alignment of the detector pairs is found by examining gamma events interacting in coincidence in both S1-S1 and S1-S2 detector combinations. Furthermore, a technique for separating neutron and gamma events in the different detector sets is presented. Finally, the time-aligned system is used to analyze neutron data from Ohmic phases for different plasma conditions and to estimate the Ohmic fuel ion temperature.

Inter-animal genetic variability exist in organoleptic properties of prime beef meat

The objective of the present study was to estimate genetic parameters for four organoleptic traits in beef meat, namely tenderness, juiciness, flavour and chewiness using data from 5380 young crossbred progeny of 748 different sires. As well as using the mean animal sensory score across all panellists for a given trait, other aggregate functions such as the median and modal values were also investigated. The heritability (SE) of mean tenderness, juiciness, flavour and chewiness was 0.16 (0.04), 0.14 (0.04), 0.11 (0.03) and 0.21 (0.06), respectively; heritability estimates for the other aggregate values of these traits were generally lower. All genetic correlations between tenderness, juiciness and flavour were positive (0.52 to 0.68) while the genetic correlations between these three traits with chewiness were all negative varying from -0.95 to -0.48. Weak genetic correlations (≤|0.16|) were evident between the sensory traits and all of carcass weight, conformation and subcutaneous fat cover.

103 A Review of Reviews of Emergency Department Interventions for Older People: Outcomes, Costs and Implementation Factors

Introduction

Older people’s emergency care is an international public health priority and remains sub-optimal in the UK. Strategies are needed to manage older patients sensitively and effectively. We reviewed emergency care interventions, evaluating evidence for outcomes, costs, and implementation.

Methods

We developed and registered (with PROSPERO, CRD42018111461) a review of reviews protocol. Screening was according to inclusion criteria for subject and reporting standards. Data were extracted and summarised in tabular and narrative form. Quality was assessed using AMSTAR2 and Joanna Briggs Institute tools. Due to intervention and outcome heterogeneity, findings were synthesised narratively. McCusker’s Elder-Friendly Emergency Department assessment tool was used as a classification framework.

Results

Eighteen review articles and three conference abstracts fulfilled inclusion criteria. The majority were systematic reviews, with four using meta-analysis. Fourteen reviews reported interventions initiated or wholly delivered within the ED, and four focussed on quality indicators or patient preferences.

Confidence was limited to each review’s interpretation of primary studies. Descriptions of interventions were inconsistent, and there was high variability in reporting standards. Interventions mostly focussed on screening and assessment, discharge planning, referrals and follow-up, and multi-disciplinary team composition and professional activities. 26 patient and health service outcomes were reported, including admissions and readmissions, length of stay, mortality, functional decline, and quality of life.

Conclusions

Our review of reviews demonstrated that the current, extensive evidence base of review studies lacks complexity, with limited or no evidence for the effectiveness of interventions; reviews commonly called for more primary research using rigorous methods. There is little review evidence for factors influencing implementation.

There was evidence that among interventions initiated in ED, those continued into the community yielded better outcomes. Service metrics (as valued by care commissioners) were evaluated as intervention outcomes more frequently than person-centred attributes (as valued by older people). Interventions were broadly holistic in nature.

Antenatal depression programs cortisol stress reactivity in offspring through increased maternal inflammation and cortisol in pregnancy: The Psychiatry Research and Motherhood - Depression (PRAM-D) Study

INTRODUCTION

Antenatal depression is associated with a broad range of suboptimal outcomes in offspring, although the underlying mechanisms are not yet understood. Animal studies propose inflammation and glucocorticoids as mediators of the developmental programming effect of prenatal stress on offspring stress responses, but studies in humans are not yet at this stage. Indeed, to date no single study has examined the effects of a rigorously defined, clinically significant Major Depressive Disorder (MDD) in pregnancy on maternal antenatal inflammatory biomarkers and hypothalamic-pituitary (HPA) axis, as well as on offspring HPA axis, behavior and developmental outcomes in the first postnatal year.

METHODS

A prospective longitudinal design was used in 106 women (49 cases vs. 57 healthy controls) to study the effect of MDD in pregnancy and associated antenatal biology (inflammatory and cortisol biomarkers), on offspring stress response (cortisol response to immunization, at 8 weeks and 12 months), early neurobehavior (Neonatal Behavioral Assessment Scale, NBAS, at day 6), and cognitive, language and motor development (Bayley Scales of Infant and Toddler Development at 12 months).

RESULTS

Compared with healthy controls, women with MDD in pregnancy had raised interleukin (IL) IL-6 (effect size (δ) = 0.53, p = 0.031), IL-10 (δ = 0.53, p = 0.043), tumor necrosis factor alpha (δ = 0.90, p = 0.003) and vascular endothelial growth factor (δ = 0.56, p = 0.008), together with raised diurnal cortisol secretion (δ = 0.89, p = 0.006), raised evening cortisol (δ = 0.64, p = 0.004), and blunted cortisol awakening response (δ = 0.70, p = 0.020), and an 8-day shorter length of gestation (δ = 0.70, p = 0.005). Furthermore, they had neonates with suboptimal neurobehavioral function in four out of five NBAS clusters measured (range of δ = 0.45-1.22 and p = 0.049-<0.001) and increased cortisol response to stress at one year of age (δ = 0.87, p < 0.001). Lastly, maternal inflammatory biomarkers and cortisol levels were correlated with infant stress response, suggesting a mechanistic link.

CONCLUSION

This study confirms and extends the notion that depression in pregnancy is associated with altered offspring behavior and biological stress response, and demonstrates that changes in maternal antenatal stress-related biology are associated with these infant outcomes.

The neutron camera upgrade for MAST Upgrade

The Neutron Camera Upgrade (NCU) is a neutron flux monitor consisting of six lines of sight (LoSs) under installation on Mega Ampere Spherical Tokamak (MAST) Upgrade. The NCU is expected to contribute to the study of the confinement of fast ions and on the efficiency of non-inductive current drive in the presence of on-axis and off-axis neutral beam injection by measuring the neutron emissivity profile along the equatorial plane. This paper discusses the NCU main design criteria, the engineering and interfacing issues, and the solutions adopted. In addition, the results from the characterization and performance studies of the neutron detectors using standard γ-rays sources and a ²⁵²Cf source are discussed. The proposed design has a time resolution of 1 ms with a statistical uncertainty of less than 10% for all MAST Upgrade scenarios with a spatial resolution of 10 cm: higher spatial resolution is possible by moving the LoSs in-between plasma discharges. The energy resolution of the neutron detector is better than 10% for a light output of 0.8 MeVee, and the measured pulse shape discrimination is satisfactory.

Heritability estimates of meat sensory characteristics are a function of the number of panellists and their inter-correlations

The objective of the present study was to quantify, using simulated data, the impact on estimated heritability of varying the number of panellists and their inter-correlations using meat sensory tenderness in cattle as an example. Estimated parameters from actual sensory-based tenderness scores from 9 individual panellists on 1252 beef cattle were used to parameterise the simulation. A single "tenderness score" for each of 10 panellists was simulated for 15,000 cattle. Heritability estimates were calculated for each of the 10 panellists individually as well as the mean score per animal for all n combinations of panellists. Heritability estimates improved with increasing number of panellists in line with expectations from a deterministic equation. The increase in heritability was due to a reduction in the residual variance, albeit the rate of reduction in residual variance declined with each additional panellist included in the calculated mean tenderness score. Results highlight the importance of reporting the number of panellist scores per animal as well as their inter-correlations in sensory-based studies.

Health services research into postnatal depression: results from a preliminary cross-cultural study

Background

Little is known about the availability and uptake of health and welfare services by women with postnatal depression in different countries.

Aims

Within the context of a cross cultural research study, to develop and test methods for undertaking quantitative health services research in postnatal depression.

Method

Interviews with service planners and the collation of key health indicators were used to obtain a profile of service avail ability and provision. A service use questionnaire was developed and administered to a pilot sample in a number of European study centres.

Results

Marked differences in service access and use were observed between the centres, including postnatal nursing care and contacts with primary care services. Rates of use of specialist services were generally low. Common barriers to access to care included perceived service quality and responsiveness. On the basis of the pilot work, a postnatal depression version of the Service Receipt Inventory was revised and finalised.

Conclusions

This preliminary study demonstrated the methodological feasibility of describing and quantifying service use, highlighted the varied and often limited use of care in this population, and indicated the need for an improved understanding of the resource needs and implications of postnatal depression.

Measurement of mother-infant interactions and the home environment in a European setting: preliminary results from a cross-cultural study

Background

Infant development is adversely affected in the context of postnatal depression. This relationship may be mediated by both the nature of early mother-infant interactions and the quality of the home environment.

Aims

To establish the usefulness of the Global Ratings Scales of Mother–Infant Interaction and the Infant–Toddler version of the Home Observation for the Measurement of the Environment (IT–HOME), and to test expected associations of the measures with characteristics of the social context and with major or minor depression.

Method

Both assessments were administered postnatally in four European centres; 144 mothers were assessed with the Global Ratings Scales and 114 with the IT–HOME. Affective disorder was assessed by means of the Structured Clinical Interview for DSM–IV Disorders.

Results

Analyses of mother–infant interaction indicated no main effect for depression but maternal sensitivity to infant behaviour was associated with better infant communication, especially for women who were not depressed. Poor overall emotional support also reduced sensitivity scores. Poor support was also related to poorer IT–HOME scores, but there was no effect of depression.

Conclusions

The Global Ratings Scales were effectively applied but there was less evidence of the usefulness of the IT–HOME.

What is Comprehensive Geriatric Assessment (CGA)? An umbrella review

Background

Comprehensive Geriatric Assessment (CGA) is now the accepted gold standard for caring for frail older people in hospital. However, there is uncertainty about identifying and targeting suitable recipients and which patients benefit the most.

Objectives

our objectives were to describe the key elements, principal measures of outcome and the characteristics of the main beneficiaries of inpatient CGA.

Methods

we used the Joanna Briggs Institute umbrella review method. We searched for systematic reviews and meta-analyses describing CGA services for hospital inpatients in the Cochrane Database of Systematic Reviews, Database of Reviews of Effectiveness (DARE), MEDLINE and EMBASE and a range of other sources.

Results

we screened 1,010 titles and evaluated 419 abstracts for eligibility, 143 full articles for relevance and included 24 in a final quality and relevance check. Thirteen reviews, reported in 15 papers, were selected for review. The most widely used definition of CGA was: 'a multidimensional, multidisciplinary process which identifies medical, social and functional needs, and the development of an integrated/co-ordinated care plan to meet those needs'. Key clinical outcomes included mortality, activities of daily living and dependency. The main beneficiaries were people ≥55 years in receipt of acute care. Frailty in CGA recipients and patient related outcomes were not usually reported.

Conclusions

we confirm a widely used definition of CGA. Key outcomes are death, disability and institutionalisation. The main beneficiaries in hospital are older people with acute illness. The presence of frailty has not been widely examined as a determinant of CGA outcome.

Calibration of neutron detectors on the Joint European Torus

The present paper describes the findings of the calibration of the neutron yield monitors on the Joint European Torus (JET) performed in 2013 using a ²⁵²Cf source deployed inside the torus by the remote handling system, with particular regard to the calibration of fission chambers which provide the time resolved neutron yield from JET plasmas. The experimental data obtained in toroidal, radial, and vertical scans are presented. These data are first analysed following an analytical approach adopted in the previous neutron calibrations at JET. In this way, a calibration function for the volumetric plasma source is derived which allows us to understand the importance of the different plasma regions and of different spatial profiles of neutron emissivity on fission chamber response. Neutronics analyses have also been performed to calculate the correction factors needed to derive the plasma calibration factors taking into account the different energy spectrum and angular emission distribution of the calibrating (point) ²⁵²Cf source, the discrete positions compared to the plasma volumetric source, and the calibration circumstances. All correction factors are presented and discussed. We discuss also the lessons learnt which are the basis for the on-going 14 MeV neutron calibration at JET and for ITER.

Theory of mind as a predictor of maternal sensitivity in women with severe mental illness

BACKGROUND

Research has shown that maternal mental illness can affect mother-infant interactions with implications for infant outcomes. Severe and chronic mental illness (SMI), particularly schizophrenia, is associated with the greatest risk. Schizophrenia is also associated with impairments in attribution of mental states, 'theory of mind' (ToM). Recent attachment research has suggested that maternal mentalizing skills are strongly associated with attachment outcome in infants. To date, no research has explored the relationship between ToM and maternal sensitivity in mothers with SMI using standard tests of ToM. The present study was designed as an exploratory study in order to investigate this.

METHOD

A total of 40 women with SMI in the postpartum period were administered a battery of ToM tasks and general neuropsychological tasks. The women were also filmed in an unstructured play session with their infants, which was coded for maternal sensitivity using the Crittenden CARE-Index.

RESULTS

One ToM task, the Frith-Happé Animations, predicted maternal sensitivity across all diagnoses. There was also an effect of diagnosis, with lower sensitivity observed in women with schizophrenia. ToM impairments did not fully explain the effect of diagnosis on sensitivity. Mothers of girls were rated as being more sensitive than mothers of boys.

CONCLUSIONS

The results suggest that ToM is a significant predictor of maternal sensitivity across all mental health diagnoses, extending the results of studies focusing on healthy populations. Clinical interventions emphasizing the importance of understanding the perspective of the infant may enhance maternal sensitivity.

Phillips-Tikhonov regularization with a priori information for neutron emission tomographic reconstruction on Joint European Torus

A method of tomographic reconstruction of the neutron emissivity in the poloidal cross section of the Joint European Torus (JET, Culham, UK) tokamak was developed. Due to very limited data set (two projection angles, 19 lines of sight only) provided by the neutron emission profile monitor (KN3 neutron camera), the reconstruction is an ill-posed inverse problem. The aim of this work consists in making a contribution to the development of reliable plasma tomography reconstruction methods that could be routinely used at JET tokamak. The proposed method is based on Phillips-Tikhonov regularization and incorporates a priori knowledge of the shape of normalized neutron emissivity profile. For the purpose of the optimal selection of the regularization parameters, the shape of normalized neutron emissivity profile is approximated by the shape of normalized electron density profile measured by LIDAR or high resolution Thomson scattering JET diagnostics. In contrast with some previously developed methods of ill-posed plasma tomography reconstruction problem, the developed algorithms do not include any post-processing of the obtained solution and the physical constrains on the solution are imposed during the regularization process. The accuracy of the method is at first evaluated by several tests with synthetic data based on various plasma neutron emissivity models (phantoms). Then, the method is applied to the neutron emissivity reconstruction for JET D plasma discharge #85100. It is demonstrated that this method shows good performance and reliability and it can be routinely used for plasma neutron emissivity reconstruction on JET.

Prospects for measuring the fuel ion ratio in burning ITER plasmas using a DT neutron emission spectrometer

The fuel ion ratio nt/nd is an essential parameter for plasma control in fusion reactor relevant applications, since maximum fusion power is attained when equal amounts of tritium (T) and deuterium (D) are present in the plasma, i.e., nt/nd = 1.0. For neutral beam heated plasmas, this parameter can be measured using a single neutron spectrometer, as has been shown for tritium concentrations up to 90%, using data obtained with the MPR (Magnetic Proton Recoil) spectrometer during a DT experimental campaign at the Joint European Torus in 1997. In this paper, we evaluate the demands that a DT spectrometer has to fulfill to be able to determine nt/nd with a relative error below 20%, as is required for such measurements at ITER. The assessment shows that a back-scattering time-of-flight design is a promising concept for spectroscopy of 14 MeV DT emission neutrons.

Forward fitting of experimental data from a NE213 neutron detector installed with the magnetic proton recoil upgraded spectrometer at JET

In this paper, we present the results obtained from the data analysis of neutron spectra measured with a NE213 liquid scintillator at JET. We calculated the neutron response matrix of the instrument combining MCNPX simulations, a generic proton light output function measured with another detector and the fit of data from ohmic pulses. For the analysis, we selected a set of pulses with neutral beam injection heating (NBI) only and we applied a forward fitting procedure of modeled spectral components to extract the fraction of thermal neutron emission. The results showed the same trend of the ones obtained with the dedicated spectrometer TOFOR, even though the values from the NE213 analysis were systematically higher. This discrepancy is probably due to the different lines of sight of the two spectrometers (tangential for the NE213, vertical for TOFOR). The uncertainties on the thermal fraction estimates were from 4 to 7 times higher than the ones from the TOFOR analysis.