Optimization of $^{178m2}$/Hf isomer production in spallation reactions at projectile energies up to 100 MeV using STAPRE and ALICE code simulations

178m2Hf isomer production in different spallation reactions with protons, a particles and neutrons at projectile energies up to 100 MeV has been analyzed using both STAPRE and ALICE code simulations. The STAPRE code was used to calculate the isomeric ratios, while the ALICE code was used to simulate the excitation functions of the respective ground states. A number of spallation reactions have been compared taking into account not only 178m2 Hf isomer productivity but also, first, the isomeric ratios calculated by the STAPRE code; second, the accumulation of the most undesirable Hf isotopes and isomers, such as 172 Hf, 175 Hf, and 179m Hf; and, third, the production of other admixtures and by-products that could degrade the quality of the produced 178m2 Hf isomer sources, including all stable Hf isotopes as well. Possibilities and ways of optimizing 178m2 Hf isomer production in spallation reactions at projectile energies up to 100 MeV are discussed. This can be considered a very important preliminary stage for accumulating such exotic nuclear isomers in lab-sized quantities at reasonable cost.