New 23Mg lifetime experiment completed
By Oliver Kirsebom
Novae are thermonuclear explosions that take place on the surface of white dwarf stars with a close companion star. With a handful detected in the Galaxy every year, these powerful explosions constitute a very common phenomenon and contribute to the enrichment of the interstellar medium. One of the isotopes thought to be produced in novae, 22Na, emits a characteristic gamma ray which, if observed, would provide a crucial test of our current understanding of novae.
In november 2012 we conducted an experiment at TRIUMF to determine the lifetime of certain excited state of the nucleus 23Mg, using the Doppler shift attenuation method at the DSAM facility. This piece of information will allow us to make a more precise estimate of the amount of 22Na produced in novae and thus a more precise estimate of the expected gamma-ray flux - which will put novae models to a stronger test if and when astronomers succeed in detecting the gamma ray from 22Na. The analysis of the experiment is in progress and we expect to have preliminary results soon.
The DSAM facility at ISAC II