Neutron Production via a Pyroelectric Crystal without a Tip

Recently, Naranjo et al.$^{1}$ and Geuther et al.$^{2}$ reported on the production of neutrons via the $^{2}$H(d,n)$^{3}$He reaction using a pyroelectric crystal with a tungsten tip attached. Here we report that neutrons can also be produced with a simpler version. Our accelerator consisted of a 2.54 cm dia x 2.54 cm LiTaO$_{3}$ crystal placed in D$_{2}$ gas of 2 mTorr without a tip and without a deuterated foil. The D$_{2}$ provided the projectiles and target atoms for the $^{2}$H(d,n)$^{3}$He reaction. When the heated (by a Peltier heater/cooler) crystal was allowed to cool to room temperature, our 12.5 cm dia x 5 cm liquid scintillator based neutron detector equipped with neutron-gamma-ray pulse-shape discrimination electronics counted 6 neutrons per minute compared to a background rate of 2 events per minute. The neutron detector was shielded by about 6 mm of Pb from the very intense X-ray radiation ($\sim $100 mR/h). The maximum ion energy and current were 200 keV and 3 nA, respectively. When H$_{2}$ was substituted for D$_{2}$, no neutron counts above background were detected. $^{1}$B. Naranjo, J.K. Gimzewski, and S. Putterman, Nature 434, 115 (2005) $^{2}$J. Geuther, Y. Danon, and F. Saglime, Phy. Rev. Lett. 96, 054803 (2006) \newline \newline *This work was supported in part by DOE grant DE-FG02-97ER41033.