What is the density of Hydrogenated Boron Nitride Nanotubes (H-BNNT)?

And I also wanted to ask if I constructed a wall made out of it, with GCRs and SEPs and Neutron radiation (basically every radiation in space) from the other side, how many kgs per m^2 of H-BNNT would be required to bring the radiation levels below the maximum permissible limit? For example, if I constructed a wall out of polyethylene, then it would be 7 metric tonnes per m^2, according to http://space.alglobus.net/papers/Easy.pdf. I want to know this value, along with the density, for H-BNNT. Please cite your sources as well, since I need to reference this.