| 1. |
- Hedqvist, Anders, et al.
(författare)
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Contributions of thermal charge exchange excitation to the Rydberg series of Cl16
- 2000
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 33:3, s. 375-382
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Tidskriftsartikel (refereegranskat)abstract
- Spectra from the Rydberg series 1s-np for the principal quantum numbers n greater than or equal to 8 of Cl16+ are observed on the JET tokamak. Individual lines up to n = 15 are resolved. The line intensity of n = 10 is enhanced, relative to the underlying 1/n(3) scaling, due to charge exchange collisions with neutral deuterium in the ground state. The observations are compared with predictions based on available partial charge exchange cross section data. There is generally good agreement, however, some details of the predicted n-shell distribution are different from those observed in the experiment.
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| 2. |
- Huber, Alexander, et al.
(författare)
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Response of the imaging cameras to hard radiation during JET operation
- 2017
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Ingår i: Fusion engineering and design. - : ELSEVIER SCIENCE SA. - 0920-3796 .- 1873-7196. ; 123, s. 669-673
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Tidskriftsartikel (refereegranskat)abstract
- The analysis of the radiation damage of imaging systems is based on all different types-of aiialoiue/digital cameras with uncooled as well as actively cooled image sensors in the VIS/NIR/MWIR spectral ranges. The Monte Carlo N-Particle (MCNP) code has been used to determine the neutron fluence at different camera locations in JET. An explicit link between the sensor damage and the neutron fluence has been observed. Sensors show an increased dark-current and increased numbers of hot-pixels. Uncooled cameras must be replaced once per year after exposure to a neutron fluence of similar to 1.9-3.2 x 10(12)neutrons/cm(2). Such levels of fluence will be reached after approximate to 14-22 ELMy H-mode pulses during the future D-T campaign. Furthermore, dynamical noise seen as a random pattern of bright pixels was observed in the presence of hard radiation (neutrons and gammas). Failure of the digital electronics inside the cameras as well as of industrial controllers is observed beyond a neutron fluence of about similar to 4 x 10(9) neutrons/cm(2). The impact of hard radiation on the different types of electronics and possible application of cameras during future D-T campaign is discussed.
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| 3. |
- Kato, Takako, et al.
(författare)
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Observations and modelling of line intensity ratios of OV multiplet line
- 1996
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 29:18, s. 4241-4253
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Tidskriftsartikel (refereegranskat)abstract
- Line intensity ratios of OV multiplet lines for the 2s3s(3)S(1)-2s3p(3)P(j) (J = 2,1,0) transitions are studied using a collisional radiative model and the results-are compared with measurements from the reversed field pinch experiments Extrap T1 and T2 at KTH. The measured line intensity ratios deviate from the predictions of the model and the possible causes for the discrepancy are discussed with regard to errors in rate coefficients and non-quasi-steady state.
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| 4. |
- Romanelli, Francesco, et al.
(författare)
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The role of JET for the preparation of the ITER exploitation
- 2011
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Ingår i: Fusion engineering and design. - : Elsevier BV. - 0920-3796 .- 1873-7196. ; 86:6-8, s. 459-464
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Tidskriftsartikel (refereegranskat)abstract
- The JET programme is devoted to the consolidation of ITER design choices and the qualification of ITER integrated regimes of operation. During the experimental campaigns carried out in 2008 and 2009 attention focussed on the test of the ITER-like ICRH antenna, the ITER scenario preparation, the verification of the adequacy of the ITER poloidal field coil design and the test of disruption mitigation methods such as massive gas injection. From 2011 the new ITER-like wall with all beryllium and tungsten plasma facing components, the neutral beam power upgrade and the enhanced control and diagnostic capability will allow key questions on plasma-wall interactions, fuel retention and plasma impurity control with the foreseen ITER wall materials to be addressed. Finally, feasibility studies have confirmed the option of installing an ITER-technology based 170 GHz/10 MW electron cyclotron resonance heating system for the control of MHD activity and the development of advanced tokamak scenarios, and 32 in-vessel coils for ELM control capable of producing magnetic perturbation spectra with a Chirikov parameter above unity for plasma currents up to 5 MA. During the ITER construction phase, JET will be the only device of its class in operation and will therefore play a key role in the preparation of ITER operations - saving time and reducing risk from the ITER programme.
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