First determination of an astrophysical cross section with a bubble chamber: the 15N(\alpha,\gamma)19F reaction

TL;DR

This paper introduces a novel bubble chamber technique for measuring astrophysical nuclear reaction cross sections with significantly higher yield and selectivity, demonstrated on the 15N(,)19F reaction, enabling future stellar rate measurements.

Contribution

It presents a new liquid bubble chamber method adapted from dark matter detection to measure nuclear reactions relevant to stars, achieving higher sensitivity and background suppression.

Findings

Successful demonstration of the bubble chamber technique with -ray beam.

Results align with R-matrix model predictions.

Potential for measuring stellar reaction rates with next-generation -ray facilities.

Abstract

We have devised a technique for measuring some of the most important nuclear reactions in stars which we expect to provide considerable improvement over previous experiments. Adapting ideas from dark matter search experiments with bubble chambers, we have found that a superheated liquid is sensitive to recoils produced from \gamma-rays photodisintegrating the nuclei of the liquid. The main advantage of the new target-detector system is a gain in yield of six orders of magnitude over conventional gas targets due to the higher mass density of liquids. Also, the detector is practically insensitive to the \gamma-ray beam itself, thus allowing it to detect only the products of the nuclear reaction of interest. The first set of tests of a superheated target with a narrow bandwidth \gamma-ray beam was completed and the results demonstrate the feasibility of the scheme. The new data are successfully described by an R-matrix model using published resonance parameters. With the increase in luminosity of the next generation \gamma-ray beam facilities, the measurement of thermonuclear rates in the stellar Gamow window would become possible.