Alpha Particle Induced Collision Cascade Fusion

Abstract

We report experimental and computational investigations of a collision-cascade mechanism to induce deuterium-deuterium (D-D) fusion. Evidence of neutron production was observed from a pressurized deuterium target exposed to energetic alpha particles emitted by a ${}^{210}\text{Po}$ source. A 5-mCi ${}^{210}\text{Po}$ alpha source was placed within a chamber containing pressurized deuterium gas, and neutron emission was monitored for 18 h using two Mirion SN-S ${}^3\text{He}$ neutron detectors. Alpha particles incident on pressurized deuterium gas produced an average excess of $\sim$74 neutrons after background subtraction, corresponding to a fusion neutron rate of $\sim$2.24 n/s. With LiD in the pressurized deuterium, the average excess increased to 268 neutrons, corresponding to 8.1 n/s. Since D-D fusion branches into two equally likely pathways, these correspond to a fusion rate near 4.5 and 16.2 fusions per second, respectively. MCNP simulations incorporating experimental geometry, source activity, and detector configuration predicted neutron yields within 5.4% of the measured values and reproduced the detector response within experimental uncertainty. The tight agreement between measured and simulated neutron counts suggests that energetic alpha-particle interactions within the deuterium may contribute to measurable D-D fusion reactions through the D(d,n)${}^3\text{He}$ channel.

10 pages, 4 figures