Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

The lithium sputtering yield from lithium and tin-lithium surfaces in the liquid state under bombardment by low-energy, singly charged particles as a function of target temperature is measured by using the Ion-surface Interaction Experiment facility. Total erosion exceeds that expected from conventional collisional sputtering after accounting for lithium evaporation for temperatures between 200 and $400\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$. Lithium surfaces treated with high-fluence D atoms are bombarded by ${\mathrm{H}}^{+}$, ${\mathrm{D}}^{+}$, ${\mathrm{He}}^{+}$, and ${\mathrm{Li}}^{+}$ at energies between 200 and $1000\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ and 45\ifmmode^\circ\else\textdegree\fi{} incidence. Erosion measurements account for temperature-dependent evaporation. For example, $700\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ ${\mathrm{He}}^{+}$ particles bombarding the D-treated liquid Li surface at room temperature result in a sputter yield of 0.12 Li/ion and at temperatures $\ensuremath{\sim}2.0{T}_{m}$ (where ${T}_{m}$ is the melting temperature of the sample), a yield near and above unity. The enhancement of lithium sputtering is observed to be a strong function of temperature and moderately on particle energy. Bombardment of a low-vapor-pressure lithium alloy (0.8 Sn-Li), used for comparison, also results in nonlinear rise of lithium erosion as a function of temperature. Measurements on both pure liquid Li and the alloy indicate a weak dependence with surface temperature of the secondary ion-induced secondary ion emission. Treatment of liquid Li surfaces with D, yields reduced sputtering under ${\mathrm{He}}^{+}$ impact by a factor of 5--6 when measured at room temperature due to preferential sputtering effects.

/pdf/collisional-and-thermal-effects-on-liquid-lithium-sputtering-4vu4j0tkgk.pdf

Collisional and thermal effects on liquid lithium sputtering

The use of liquid walls for fusion reactors could help solve problems associated with material erosion from high plasma heat-loads and neutronic activation of structures. A key issue analyzed here is the influx of impurity ions to the core plasma from the vapor of liquid side-walls. Numerical 2D transport simulations are performed for a slab geometry which approximates the edge region of a reactor-size tokamak. Both lithium vapor (from Li or SnLi walls) and fluorine vapor (from Flibe walls) are considered for hydrogen edge-plasmas in the high- and low-recycling regimes. It is found that the minimum influx is from lithium with a low-recycling hydrogen plasma, and the maximum influx occurs for fluorine with a high-recycling hydrogen plasma.

/pdf/interactions-between-liquid-wall-vapor-and-edge-plasmas-kwd7d6hg2p.pdf

Interactions between Liquid-Wall Vapor and Edge Plasmas

Developing a reactor-compatible divertor has been identified as a particularly challenging technology problem for magnetic confinement fusion. Application of lithium (Li) in NSTX resulted in improved H-mode confinement, H-mode power threshold reduction, and other plasma performance benefits. During the 2010 NSTX campaign, application of a relatively modest amount of Li (300 mg prior to the discharge) resulted in a ∼50% reduction in heat load on the liquid lithium divertor (LLD) attributable to enhanced divertor bolometric radiation. These promising Li results in NSTX and related modelling calculations motivated the radiative LLD concept proposed here. Li is evaporated from the liquid lithium (LL) coated divertor strike-point surface due to the intense heat flux. The evaporated Li is readily ionized by the plasma due to its low ionization energy, and the poor Li particle confinement near the divertor plate enables ionized Li ions to radiate strongly, resulting in a significant reduction in the divertor heat flux. This radiative process has the desired effect of spreading the localized divertor heat load to the rest of the divertor chamber wall surfaces, facilitating the divertor heat removal. The LL coating of divertor surfaces can also provide a ‘sacrificial’ protective layer to protect the substrate solid material from transient high heat flux such as the ones caused by the edge localized modes. By operating at lower temperature than the first wall, the LL covered large divertor chamber wall surfaces can serve as an effective particle pump for the entire reactor chamber, as impurities generally migrate towards lower temperature LL divertor surfaces. To maintain the LL purity, a closed LL loop system with a modest circulating capacity (e.g., ∼1 l s−1 for ∼1% level ‘impurities’) is envisioned for a steady-state 1 GW-electric class fusion power plant.

https://iopscience.iop.org/article/10.1088/0029-5515/53/11/113030/pdf

Recent progress in the NSTX/NSTX-U lithium programme and prospects for reactor-relevant liquid-lithium based divertor development

Liquid metal (LM) plasma-facing components (PFCs) may provide a resolution to the challenging fusion environment, particularly the first wall and divertor surfaces. Transforming these conce...

Critical Exploration of Liquid Metal Plasma-Facing Components in a Fusion Nuclear Science Facility

http://cpmi.illinois.edu/files/2015/04/2004-Allain-Nieto-Coventry-Stubbers-Ruzic.pdf

Studies of liquid-metal erosion and free surface flowing liquid lithium retention of helium at the University of Illinois

http://cpmi.illinois.edu/files/2015/04/Nieto_Helium-retention-and-diffusivity-in-flowing-liquid-lithium.pdf

Helium retention and diffusivity in flowing liquid lithium

https://cpmi.illinois.edu/files/2015/04/2002-Allain-Nieto-Coventry-Neumann-Vargas-Lopes-Ruzic.pdf

FLIRE*/flowing liquid surface retention experiment, design and testing

https://cpmi.illinois.edu/files/2015/04/2005-Stubbers-Olczak-Nieto-Ruzic.pdf

Measurement of hydrogen absorption in flowing liquid lithium in the flowing lithium retention experiment (FLIRE)

https://cpmi.illinois.edu/files/2015/04/2006-Nieto-Ruzic-Olczak-Stubbers.pdf

M. Nieto

Papers

Studies of liquid-metal erosion and free surface flowing liquid lithium retention of helium at the University of Illinois

Helium retention and diffusivity in flowing liquid lithium

FLIRE*/flowing liquid surface retention experiment, design and testing

Measurement of hydrogen absorption in flowing liquid lithium in the flowing lithium retention experiment (FLIRE)

Measurement of implanted helium particle transport by a flowing liquid lithium film