There are three principle options for future beam based neutrino oscillation facilities that could discover and measure CP-violation in the lepton sector. These are conventional Super-Beams, Neutrino ...Factories and Beta Beams. Several projects have been taking place world-wide to study examples of these facilities. In Europe, one of the most important of these is the Framework Programme 7 supported project, EUROnu. These projects are in the process of identifying experimental R&D work that must be done before a technical design of the facility can be finalised and construction started. This paper will summarise this work for each type of facility, based largely on what has been done in EUROnu.
► New experimental data on the yield strength of molybdenum, tantalum and tungsten. ► High strain rate effects at record high temperatures (up to 2700K). ► Test of the consistency of the ...Zerilli–Armstrong model at very high temperatures.
Recently reported results of the high strain rate, high temperature measurements of the yield strength of tantalum and tungsten have been analyzed along with new experimental results on the yield strength of molybdenum. Thin wires are subjected to high stress by passing a short, fast, high current pulse through a thin wire; the amplitude of the current governs the stress and the repetition rate of the pulses determines the temperature of the wire. The highest temperatures reached in the experiments were 2100°C (for molybdenum), 2250°C (for tantalum) and 2450°C (for tungsten). The strain-rates in the tests were in the range from 500 to 1500s−1. The parameters for the constitutive equation developed by Zerilli and Armstrong have been determined from the experimental data and the results have been compared with the data obtained at lower temperatures. An exceptionally good fit is obtained for the deformation of tungsten.
EMMA—The world’s first non-scaling FFAG Barlow, R; Berg, J.S.; Beard, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2010, Letnik:
624, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Due to the combination of fixed magnetic field operation with strong focusing, non-scaling FFAGs have a significant potential for future particle accelerator applications. However, this technology ...has a number of unique features, which must be fully studied before this potential can be realised. To do this, a proof-of-principle non-scaling FFAG, called EMMA – Electron Model for Many Applications – has been constructed at the STFC Daresbury Laboratory in the UK. It has been designed by an international collaboration of accelerator scientists and engineers. It will demonstrate the principle of non-scaling FFAGs and be used to study the features of this type of accelerator in detail.
Recently reported results of the long lifetime of the tungsten samples under high temperature and high stress conditions expected in the Neutrino Factory target have strengthened the case for a solid ...target option for the Neutrino Factory. In order to study in more detail the behaviour of the material properties of tungsten, a dynamic method has been used for measurement of Young’s modulus at high stress, high-strain-rates (>1000
s
−1) and very high temperatures (up to 2650
°C). The method is based on measurements of the surface vibration of thin wires, stressed by a pulsed current, using a Laser Doppler Vibrometer. The measured characteristic frequencies under the thermal excitation have been used to obtain Young’s modulus as a function of applied stress and temperature. The same procedure has been used to measure Young’s modulus of tantalum up to 2500
°C.
With the move towards beam power in the range of 1–10 MW, a thorough understanding of the response of target materials and auxiliary systems to high power densities and intense radiation fields is ...required. This paper provides insight into three major aspects related to the design and operation of high power solid targets: thermal stresses, coolant performance, and radiation damage. Where appropriate, a figure-of-merit approach is followed to facilitate the comparison between different target or coolant candidates. The section on radiation damage reports total and spatial variations of displacement-per-atom and helium production levels in different target materials.
A description of lifetime shock tests on tantalum and tungsten is given and of modelling studies as part of the research into solid targets for a Neutrino Factory. A fast high current pulse is ...applied to a thin wire of the sample material and the number of pulses measured before the wire visibly deteriorates. These measurements are made at temperatures up to ∼2000
K. The stress on the wire is calculated and compared to the stress expected in the target using the computer code LS-DYNA. It has been found that tantalum is too weak to sustain prolonged stress at these temperatures but a tungsten wire has reached over 13 million pulses (equivalent to 10 years of operation) at the stress expected in the target. Further work is in progress to study graphite and other materials. Measurement of the surface acceleration of the wire using a VISAR are to be made, which, combined with LS-DYNA modelling, will allow the evaluation of the constitutive equations of state of the materials at high temperature and provide a more accurate model of the stresses in a number of target geometries.
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