| 41. |
- Brezinsek, S., et al.
(författare)
-
Erosion, screening, and migration of tungsten in the JET divertor
- 2019
-
Ingår i: Nuclear Fusion. - : IOP PUBLISHING LTD. - 0029-5515 .- 1741-4326. ; 59:9
-
Tidskriftsartikel (refereegranskat)abstract
- The erosion of tungsten (W), induced by the bombardment of plasma and impurity particles, determines the lifetime of plasma-facing components as well as impacting on plasma performance by the influx of W into the confined region. The screening of W by the divertor and the transport of W in the plasma determines largely the W content in the plasma core, but the W source strength itself has a vital impact on this process. The JET tokamak experiment provides access to a large set of W erosion-determining parameters and permits a detailed description of the W source in the divertor closest to the ITER one: (i) effective sputtering yields and fluxes as function of impact energy of intrinsic (Be, C) and extrinsic (Ne, N) impurities as well as hydrogenic isotopes (H, D) are determined and predictions for the tritium (T) isotope are made. This includes the quantification of intra- and inter-edge localised mode (ELM) contributions to the total W source in H-mode plasmas which vary owing to the complex flux compositions and energy distributions in the corresponding phases. The sputtering threshold behaviour and the spectroscopic composition analysis provides an insight in the dominating species and plasma phases causing W erosion. (ii) The interplay between the net and gross W erosion source is discussed considering (prompt) re-deposition, thus, the immediate return of W ions back to the surface due to their large Larmor radius, and surface roughness, thus, the difference between smooth bulk-W and rough W-coating components used in the JET divertor. Both effects impact on the balance equation of local W erosion and deposition. (iii) Post-mortem analysis reveals the net erosion/deposition pattern and the W migration paths over long periods of plasma operation identifying the net W transport to remote areas. This W transport is related to the divertor plasma regime, e.g. attached operation with high impact energies of impinging particles or detached operation, as well as to the applied magnetic configuration in the divertor, e.g. close divertor with good geometrical screening of W or open divertor configuration with poor screening. JET equipped with the ITER-like wall (ILW) provided unique access to the net W erosion rate within a series of 151 subsequent H-mode discharges (magnetic field: B-t = 2.0 T, plasma current: I-p = 2.0 MA, auxiliary power P-aux = 12 MW) in one magnetic configuration accumulating 900 s of plasma with particle fluences in the range of 5-6 x 10(26) D(+ )m(-2) in the semi-detached inner and attached outer divertor leg. The comparison of W spectroscopy in the intra-ELM and inter-ELM phases with post-mortem analysis of W marker tiles provides a set of gross and net W erosion values at the outer target plate. ERO code simulations are applied to both divertor leg conditions and reproduce the erosion/deposition pattern as well as confirm the high experimentally observed prompt W re-deposition factors of more than 95% in the intra- and inter-ELM phase of the unseeded deuterium H-mode plasma. Conclusions to the expected divertor conditions in ITER as well as to the JET operation in the DT plasma mixture are drawn on basis of this unique benchmark experiment.
|
|
| 42. |
|
|
| 43. |
- Forsberg, Fredrik, et al.
(författare)
-
CMOS-integrated Si/SiGe quantum-well infrared microbolometer focal plane arrays manufactured with very large-scale heterogeneous 3-d integration
- 2015
-
Ingår i: IEEE Journal of Selected Topics in Quantum Electronics. - : Institute of Electrical and Electronics Engineers Inc.. - 0792-1233 .- 1077-260X .- 1558-4542. ; 21:4
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate infrared focal plane arrays utilizing monocrystalline silicon/silicon-germanium (Si/SiGe) quantum-well microbolometers that are heterogeneously integrated on top of CMOS-based electronic read-out integrated circuit substrates. The microbolometers are designed to detect light in the long wavelength infrared (LWIR) range from 8 to 14 μm and are arranged in focal plane arrays consisting of 384 × 288 microbolometer pixels with a pixel pitch of 25 μm × 25 μm. Focal plane arrays with two different microbolometer designs have been implemented. The first is a conventional single-layer microbolometer design and the second is an umbrella design in which the microbolometer legs are placed underneath the microbolometer membrane to achieve an improved pixel fill-factor. The infrared focal plane arrays are vacuum packaged using a CMOS compatible wafer bonding and sealing process. The demonstrated heterogeneous 3-D integration and packaging processes are implemented at wafer-level and enable independent optimization of the CMOS-based integrated circuits and the microbolometer materials. All manufacturing is done using standard semiconductor and MEMS processes, thus offering a generic approach for integrating CMOS-electronics with complex miniaturized transducer elements
|
|
| 44. |
- Giacomelli, L., et al.
(författare)
-
Neutron emission spectroscopy results for internal transport barrier and mode conversion ion cyclotron resonance heating experiments at JET
- 2008
-
Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 79:10, s. 10E514-
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of ion cyclotron resonance heating (ICRH) on ((3)He)D plasmas at JET was studied with the time of flight optimized rate (TOFOR) spectrometer dedicated to 2.5 MeV dd neutron measurements. In internal transport barrier (ITB) plasma experiments with large (3)He concentrations (X((3)He)>15%) an increase in neutron yield was observed after the ITB disappeared but with the auxiliary neutral beam injection and ICRH power still applied. The analysis of the TOFOR data revealed the formation of a high energy (fast) D population in this regime. The results were compared to other mode conversion experiments with similar X((3)He) but slightly different heating conditions. In this study we report on the high energy neutron tails originating from the fast D ions and their correlation with X((3)He) and discuss the light it can shed on ICRH-plasma power coupling mechanisms.
|
|
| 45. |
- Nocente, M., et al.
(författare)
-
High-resolution gamma ray spectroscopy measurements of the fast ion energy distribution in JET He-4 plasmas
- 2012
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 52:6, s. 063009-
-
Tidskriftsartikel (refereegranskat)abstract
- High-resolution gamma-ray measurements were carried out on the Joint European Torus (JET) in an experiment aimed at accelerating He-4 ions in the MeV range by coupling third harmonic radio frequency heating to an injected He-4 beam. For the first time, Doppler broadening of gamma-ray peaks from the C-12(d, p gamma)C-13 and Be-9(alpha, n gamma)C-12 reactions was observed and interpreted with dedicated Monte Carlo codes based on the detailed nuclear physics of the processes. Information on the confined He-4 and deuteron energy distribution was inferred, and confined He-4 ions with energies as high as 6 MeV were assessed. A signature of MHD activity in gamma-ray traces was also detected. The reported results have a bearing on diagnostics for fast ions in the MeV range in next step fusion devices.
|
|
| 46. |
|
|
| 47. |
- Start, DFH, et al.
(författare)
-
Bulk ion heating with ICRH in JET DT plasmas
- 1999
-
Ingår i: NUCLEAR FUSION. - 0029-5515. ; 39:3, s. 321-336
-
Tidskriftsartikel (refereegranskat)abstract
- Reactor relevant ICRH scenarios have been assessed during DT experiments on the JET tokamak using H mode divertor discharges with ITER-like shapes and safety factors. Deuterium minority heating in tritium plasmas was demonstrated for the first time. For 9
|
|
| 48. |
- Amgad, M, et al.
(författare)
-
Report on computational assessment of Tumor Infiltrating Lymphocytes from the International Immuno-Oncology Biomarker Working Group
- 2020
-
Ingår i: NPJ breast cancer. - : Springer Science and Business Media LLC. - 2374-4677. ; 6:1, s. 16-
-
Tidskriftsartikel (refereegranskat)abstract
- Assessment of tumor-infiltrating lymphocytes (TILs) is increasingly recognized as an integral part of the prognostic workflow in triple-negative (TNBC) and HER2-positive breast cancer, as well as many other solid tumors. This recognition has come about thanks to standardized visual reporting guidelines, which helped to reduce inter-reader variability. Now, there are ripe opportunities to employ computational methods that extract spatio-morphologic predictive features, enabling computer-aided diagnostics. We detail the benefits of computational TILs assessment, the readiness of TILs scoring for computational assessment, and outline considerations for overcoming key barriers to clinical translation in this arena. Specifically, we discuss: 1. ensuring computational workflows closely capture visual guidelines and standards; 2. challenges and thoughts standards for assessment of algorithms including training, preanalytical, analytical, and clinical validation; 3. perspectives on how to realize the potential of machine learning models and to overcome the perceptual and practical limits of visual scoring.
|
|
| 49. |
|
|
| 50. |
|
|
