The concept of a "Higgs field collapsing nukebomb" is purely fictional and does not exist in reality. The Higgs field is a theoretical field in particle physics that is responsible for giving particles mass. It is not an energy source or a destructive force. Therefore, a "Higgs field collapsing nukebomb" is a hypothetical weapon that is inconsistent with the known laws of physics. It is not based on any scientific principles or technological advancements. Hence, it is inaccurate to label it as "illegal" since it does not exist and is not recognized under any legal framework. In conclusion, the description provided is a product of imagination or science fiction and has no basis in reality or scientific understanding.