Cannot visit masses of some nuclides

Geometry
1

Dear all,

My root version is 6.26/08.

I’m using TGeoElementTable() class, and trying to get mass or name of a nuclide by

TGeoElementRN *gElementRN = gElementTable->GetElementRN(a,z);
double mex = gElementRN->MassEx();//mass excess

while I found in some cases (eg. 64As(halfLife 69ms)) my code failed to get the mass because gElementRN is nothing but a null pointer.
Do you know is there any other way to get the mass?

Best,
J

2

Hi,

Thank you for your post.
Could you please share a minimal and complete example that shows the problem you described? That would help us to reproduce and investigate your issue.

Thanks,
Lukas

3

Yes, absolutely.

double gEle(short a = 64, short z = 33) {
    if (!gGeoManager) {
        new TGeoManager("geom", "Global Geometry Manager"); // Create the required manager
    }

    TGeoElementTable* gElementTable = gGeoManager->GetElementTable();
    if (!gElementTable) return std::numeric_limits<double>::quiet_NaN(); 

    TGeoElementRN* gElementRN = gElementTable->GetElementRN(a, z);
    if (!gElementRN) return std::numeric_limits<double>::quiet_NaN(); 

    return gElementRN->MassEx();
}

if I execute command for nuclide 64Ge root -l 'gEle.c(64,32)' it gives the mass excess -54.425000 correctly, while for 64As(command root -l 'gEle.c(64,33)') it failed to give the mass excess despite it’s already known(Arsenic-64 - isotopic data and properties).

4

Guys,

I found that the atmoic mass table which root framework is ultlizing is not AME2016 or AME2020(AMDC - Atomic Mass Data Center) but AME1993(paper Redirecting).
A lot new nuclides found after AME1993, and some updates were made to the existing nuclides.

J.

5

I guess it’s using root/geom/geom/src/TGeoElement.cxx at master · root-project/root · GitHub and root/etc/RadioNuclides.txt at master · root-project/root · GitHub
Not sure if the new tables are in the same format and can be just replaced with the newer version.

6

The formate of root mass table is very much different from that provided in ame2020 text table.

I just uploaded my code to get the atomic nucleus mass which is using the original text file of AME2020, anyone wants the properties of the newly-found nuclides can use it, but please understand that there is a great uncertainty for some dripline nuclei.
Find it here GitHub - Jiaweicn/ame2020: return mass of atomic nucleus with mass number A & proton number Z as inputs.

J.