Bubble Chamber : A novel technique for measuring thermonuclear rates at low energies

Adopting ideas from dark matter search experiments, we have found that a superheated liquid in a bubble detector is sensitive to recoils produced by $\gamma$-ray beams impinging on the nuclei in the liquid. Such a target-detector system has a density factor of four orders of magnitude higher than conventional gas targets and is practically insensitive to the $\gamma$-ray beam itself. Also, since photodisintegration reactions have approximately two orders of magnitude higher cross-sections than direct particle capture reactions, such a technique can pave the way towards measuring these reactions within the stellar Gamow window. In an effort to study the $^{16}$O($\gamma,\alpha$)$^{12}$C system using the bubble chamber technique, the first test of the superheated N$_2$O liquid with a low-energy bremsstrahlung beam at JLab has been completed. This test has been performed to understand the background contributions from $^{17}$O and $^{18}$O nuclei in N$_2$O. The experimental technique, results and future plans will be presented.