WIMP detection and slow ion dynamics in carbon nanotube arrays

TL;DR

This paper explores the potential of aligned carbon nanotube arrays as a target for detecting low-mass WIMPs by analyzing ion dynamics and proposing optimized array configurations for improved detection efficiency.

Contribution

It introduces a novel approach to WIMP detection using CNT arrays and provides new constraints on array design based on ion motion analysis at low energies.

Findings

Identified conditions for ion emergence from CNTs after WIMP interactions

Derived constraints on CNT array orientation for optimal detection

Analyzed low-energy ion trajectories in 2D lattice models

Abstract

Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (~ 10 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the detection efficiency.