Beta decay is presented in this lecture. The neutrino hypothesis and its relationship with beta decay is discussed. A review of Q value calculations for beta decay is provided. The importance of spin and parity, and how it can be used to assess beta decay, is discussed. Modeling beta decay through the weak force is provided.. The impact of Coulomb interactions on positron and electron spectral shape is presented. The use of Kurie plots in understanding beta decay is introduced. Selection rules in beta decay and beta transitions are explained. Calculating logft and its relation to spin and parity are presented. Double beta decay is discussed.
I had to watch the lecture a couple times before I felt a little more comfortable with the reasoning behind spectral shape; getting the hang of calculating the log ft values and interpreting the implied transitions from those values now.
ReplyDeleteI was just reading that double beta decay was first observed by a research group over at UC Irvine, just 4 years before I was born. Seems like a pretty rare phenomena. Definitely looking forward to our trip over there this summer.
For the calculation of the log (ft) value for the decay of Ti45, I'm getting some mixed information when it comes to the decay mode. In the chart of the nuclides it appears that there are two modes of decay, beta+ and electron capture.
ReplyDeleteWhen using the nuclear wallet cards from the NNDC to find the decay mode, only electron capture is given with no branching percentage:
http://www.nndc.bnl.gov/wallet/zz11/z022.html
I'm wondering if I I should just calculate the log (f) values using each formula for beta+ and electron capture separately, neglecting branching decay?
That would work
DeleteThis was another very interesting lecture on decay theory. Spin and Parity have certainly caught my attention, as they have shown significant importance in predicting decays.
ReplyDeleteThanks!
DeleteCool stuff. I'm glad spin and parity are showing up some more and having a purpose. What drives 1st, 2nd, 3rd, and 4th forbidden transitions? They seem super energetically unfavored.
ReplyDeleteThe energetics drive the decay. The poor spin and parity means the probability is poor. This means a longer half life.
DeleteFinished lecture. I had the same question as Zach for Ti45 and after watching the gamma decay lecture my guess is what's happening is that Ti45 B+ decays to an excited state of Sc45* and then decays through electron capture separately to the ground state. (I think?) each of these transitions would have their own log ft value?
ReplyDeleteCool lecture, this one definitely takes a lot more concentration and time to understand thoroughly.
ReplyDeleteLet me know if you think it should be in two parts.
DeleteI like the brief mention of double beta decay. It's like the middle child of B decay no one ever mentions.
ReplyDeletethanks!
ReplyDeleteI listened to this lecture.
ReplyDeletethanks for the note
ReplyDelete