U238 decay chain about bxdecay0 HOT 10 CLOSED

By the way, with the correct data, it doesn't look to be too complicated for me to implement it, so if that data is somewhere in hand, I'm happy to do it and go through the usual pull request process.

from bxdecay0.

Hi Pierre,

You are right, the current version of BxDecay0, as a port of decay0 release "2020-04-20" (with a few additional features), does not contain the decay schemes for (here for the U238 chain):

• U238
• U234
• Th230
• Rn222
• Po218
• Po210

Note: Po214 is included as a cascade in Bi214 decay.

My guess is that the legacy decay0 has concentrated mostly on beta emitters because they are usually the more dangerous background providers for double beta decay experiments.
However, Vladimir may have some variant of his Fortran code that contains such decay models (or part of them) with alpha emitters (useful for dark matter/HPGe and other crystal based experiments with surface contamination issues).
Let me ask him before to go further and then we will see what can be done.

from bxdecay0.

Note that the reference you gave reflects the features in the decay4 program (not decay0). decay4 is likely a variant of decay0 and probably implement functionalities that are a little different from decay0. Vladimir will say more about it.

from bxdecay0.

Note also that Rn222 would be useful too for educational simulation project (alpha spectrometry lab...)

from bxdecay0.

I see, thanks. I hadn't noticed the difference.

from bxdecay0.

I have no access to the original decay4 code too and I don't know if it is still maintained by Vladimir. So let's wait and see. I sent a message to him.

from bxdecay0.

Excerpt from Vlad's answer:

By the way, one of reasons why I did not create independent subroutines for specific alpha
decayers, is that many of them decay mainly to the
ground daughter state (e.g. 99.92% for 222-Rn). So, their decays can be
easily generated with the so called "artificial event" in Decay0, when one
can construct artificial decay consisting of up to 10 parts, and each part
can be alpha or beta particle or pions, etc. So, for 99.92% of 222-Rn one
can use "art. event" consisting of 1 part, and this part is emission of
alpha particle with E=5.590/222*218=5.489 MeV.

The point is that BxDecay0 does not port the "artificial event" from Decay0 because
originally the Bayeux library has its own "universal single particle generator" so I had
no need for this kind of stuff so far and also because the alpha emitters are of no interest for the SuperNEMO usecase.

However, Vladimir is ok to provide in decay0 the missing alpha decayers you will ask.
In the meanwhile, we/you can implement very simplified version of them (only dominant alpha decays) in BxDecay0.
I think this approach is rather good for it would make the BxDecay0 interface more uniform and complete and also users won't have to know the details of all the decay schemes (Q-values, branching ratios...) associated to these isotopes.
This work could be also updated by expert people like Vladimir to take into account fine effects like internal conversion...

from bxdecay0.

As an exercise, I have added a simple Rn222 alpha generator with support for ground (0+) and 513 keV (2+) levels of Po218 (NDC: https://www.nndc.bnl.gov/nudat2/chartNuc.jsp).

New files are:

• bxdecay0/Rn222.h
• bxdecay0/Rn222.cc

Modified files:

• bxdecay0/genbbsub.cc (search for "Rn222" string)
• CMakeLists.txt

from bxdecay0.

Hi,
I see, that doesn't look terribly complicated.
The thing that does look complicated and error prone is parsing the NNDC website :s

I'll give it a go for the next decays.

from bxdecay0.

Hmmm, nuclear data tables are not famous for their clarity and accessibility for modern software interface.

from bxdecay0.