The present experimental status of the xi(2230) is summarized and several possible interpretations are discussed.
... H. Schmitt et al./Strangeness production with antiprotons 173 DISCUSSION IS Shapiro (Lebedev Physical Instltute): I. The near threshold AA data are of greatest interest. Will the statistics be improved in the near future? ... 16} IS... more
... H. Schmitt et al./Strangeness production with antiprotons 173 DISCUSSION IS Shapiro (Lebedev Physical Instltute): I. The near threshold AA data are of greatest interest. Will the statistics be improved in the near future? ... 16} IS Shapiro, Proc. ...
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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.,... more
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.
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A method to generate modeled neutron spectra from bulk and fast ion distributions simulated by TRANSP has been developed. In this paper, modeled data generated from fuel ion distributions modeled with TRANSP is compared to measured data... more
A method to generate modeled neutron spectra from bulk and fast ion distributions simulated by TRANSP has been developed. In this paper, modeled data generated from fuel ion distributions modeled with TRANSP is compared to measured data from two neutron spectrometers with different lines of sight; TOFOR with a radial one and the MPRu with a tangential one. The information obtained from the analysis of the measured neutron spectra such as the relative intensity of the emission from different ion populations places additional constraints on the simulation and can be used to adjust the parameters of the simulation.
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Research Interests: Haematology and Capture
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Summary The reaction $$\bar pp \to \bar \Lambda \Lambda $$ is related to the creation of a strange-antistrange quark pair. It is studied at LEAR. Total and differential cross-sections, as well as $$\bar \Lambda $$ and Λ polarization and... more
Summary The reaction $$\bar pp \to \bar \Lambda \Lambda $$ is related to the creation of a strange-antistrange quark pair. It is studied at LEAR. Total and differential cross-sections, as well as $$\bar \Lambda $$ and Λ polarization and spin correlation data were obtained. First results on the reaction $$\bar p$$ p→KSKS in the energy range of the $$\bar \Lambda $$ Λ threshold can be shown. Future possibilities of the experiment are indicated.
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ABSTRACT A central task for fusion plasma diagnostics is to measure the 2.5 and 14 MeV neutron emission rate in order to determine the fusion power. A new method for determining the neutron yield has been developed at JET. It makes use of... more
ABSTRACT A central task for fusion plasma diagnostics is to measure the 2.5 and 14 MeV neutron emission rate in order to determine the fusion power. A new method for determining the neutron yield has been developed at JET. It makes use of the magnetic proton recoil neutron spectrometer and a neutron camera and provides the neutron yield with small systematic errors. At ITER a similar system could operate if a high-resolution, high-performance neutron spectrometer similar to the MPR was installed. In this paper, we present how such system could be implemented and how well it would perform under different assumption of plasma scenarios and diagnostic capabilities. It is found that the systematic uncertainty for using such a system as an absolute calibration reference is as low as 3 % and hence it would be an excellent candidate for the calibration of neutron monitors such as fission chambers. It is also shown that the system could provide a 1 ms time resolved estimation of the neutron rate with a total uncertainty of 5 %.
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ABSTRACT Tomographic reconstruction techniques typically require computationally intensive algorithms which are not suitable for real-time application. This paper describes a framework to perform neutron emissivity tomography at the Joint... more
ABSTRACT Tomographic reconstruction techniques typically require computationally intensive algorithms which are not suitable for real-time application. This paper describes a framework to perform neutron emissivity tomography at the Joint European Torus (JET) using neural networks with successful results over a broad range of magnetic configurations, heating and fueling schemes. Application times in the μs time scale allows for real-time applicability of the method.
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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... more
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.
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An evaluation of three different candidate techniques for a 14-MeV High Resolution Neutron Spectrometer for a high power fusion device is presented. The performance is estimated for a modelled neutron emission for ITER plasma scenario 4.... more
An evaluation of three different candidate techniques for a 14-MeV High Resolution Neutron Spectrometer for a high power fusion device is presented. The performance is estimated for a modelled neutron emission for ITER plasma scenario 4. As performance indicators we use the estimated time-resolution achieved in measurements of three plasma parameters, namely, the ion temperature, the intensity of neutron emission
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uu.se. Publications. ...
Results from the experiment PS 185 investigating the production of antilambda (Λ¯) lambda (Λ) and K° K°¯ out of the antiproton (p¯) proton (p) annihilation are reported. In particular, the threshold measurements of the reaction p¯p↠Λ¯Λ is... more
Results from the experiment PS 185 investigating the production of antilambda (Λ¯) lambda (Λ) and K° K°¯ out of the antiproton (p¯) proton (p) annihilation are reported. In particular, the threshold measurements of the reaction p¯p↠Λ¯Λ is discussed. From the shapes of the excitation function and of the angular distribution higher angular momentum contributions are conclued even at enegies close to to threshold. An interconnection of Λ¯Λ and the K°¯ K˙ channels to the &xgr;(2230) resonance is search for.
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In Sweden, there is a longstanding conflict between the use of forests for timber production and game for hunting due to browsing damages on young forests. This study examines the assessments of two stakeholder groups regarding browsing... more
In Sweden, there is a longstanding conflict between the use of forests for timber production and game for hunting due to browsing damages on young forests. This study examines the assessments of two stakeholder groups regarding browsing damage by moose. The data originated from a mail survey that involved hunters and forest owners in Sweden. The samples were randomly selected
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A new control and monitoring (C&M) system is being developed for the TOFOR and MPRu fusion neutron spectrometers within the Joint European Torus enhancement program. The system, which is an evolution of the existing C&M system of... more
A new control and monitoring (C&M) system is being developed for the TOFOR and MPRu fusion neutron spectrometers within the Joint European Torus enhancement program. The system, which is an evolution of the existing C&M system of the MPR spectrometer, consists of a controlled pulsed light source distributed by an optical fiber network to all photomultiplier tubes used in the plastic scintillator based spectrometers. The light source is a green Nd:LSB solid-state laser complemented by blue light emitting diode sources. Pulse height distributions for each detection channel are recorded to set the spectrometers to prescribed working points and monitor deviations. Absolute reference is obtained complementing the controlled light source with radioactive sources. In this article we report on the C&M prototype design and component tests for the MPRu spectrometer. The results show that the laser and the associated optics provide a controlled light pulse of intensity covering a dynamic range of more than four orders of magnitude. The choice of optical fiber diameters is critical for achieving the desired stability and uniformity of the light intensity collected by each MPRu detector.
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... Portugal J. Kaellne INF, Uppsala University, EURATOM-VR Association, Box 535, 75 121 Uppsala, Sweden V. Kiptily and K. Lawson EURATOM/UKAEA ... For the diagnosis of the fusion products, a new approach is being developed to measure the... more
... Portugal J. Kaellne INF, Uppsala University, EURATOM-VR Association, Box 535, 75 121 Uppsala, Sweden V. Kiptily and K. Lawson EURATOM/UKAEA ... For the diagnosis of the fusion products, a new approach is being developed to measure the He ash based on double ...
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Spectrometry of the neutron emission is discussed as a probe of the fuel ion velocity distribution in tokamak plasmas where the instrumental energy calibration allows determination of Doppler shifts on an absolute scale or relative to the... more
Spectrometry of the neutron emission is discussed as a probe of the fuel ion velocity distribution in tokamak plasmas where the instrumental energy calibration allows determination of Doppler shifts on an absolute scale or relative to the emission of thermal plasma conditions. Such Doppler shifts have been measured for plasmas of different heating methods at the Joint European Torus (JET)