Speaker
Description
Maulik Panchal1,, Harsh Patel1, Paritosh Chaudhuri1,2
1Institute for Plasma Research, Bhat, Gandhinagar - 382428, India.
2Homi Bhabha National Institute, Anushaktinagar, Mumbai - 400094, India.
E-mail address: maulikpanchal@ipr.res.in
Accurate prediction of thermal performance within the breeder zones of fusion blankets is critically dependent on the effective thermal conductivity (keff) of ceramic pebble beds. These beds, typically composed of lithium-based ceramics such as lithium titanate (Li₂TiO₃), exhibit anisotropic thermal behaviour when subjected to significant mechanical stresses and steep thermal gradients during operation of fusion reactor. While numerous studies have reported keff values under isotropic assumptions, such simplifications overlook the inherent directionality in heat transport arising from random packing, surface roughness, preferential contact orientation, and the non-spherical shape of pebbles. Previous studies have often assumed isotropic keff, which can lead to significant inaccuracies in thermal modeling, potentially impacting tritium breeding efficiency and structural integrity.
To address this gap, we have developed and implemented an experimental methodology based on the transient hot-wire technique to independently measure keff in both axial and radial directions. The experimental setup incorporates dual hot-wire probes aligned along orthogonal axes, enabling direct quantification of anisotropic keff in compressed pebble beds. This approach allows for systematic evaluation of how mechanical compaction influences directional heat transport in realistic breeder configurations. The experiments are designed to be conducted across a range of compressive stresses and at temperatures relevant to fusion blanket operation. The experimental methodology, measurements, and key findings will be presented and discussed.
