“…One is the gas driven model [62][63][64], in which bubbles are assumed to grow by coalescence or the loop punching mechanism [65]. As more deuterium is deposited and bubbles grow, cooperative fracture between the bubbles suddenly becomes an easy way of relieving their overpressure, thus initiating cracks, allowing internal gas release, and lifting the surface off the implanted material into dome-shaped blisters.…”