Irradiating a graphite target coated with silicon glue is generally advisable, as both materials exhibit low neutron absorption and behave similarly under beta or photon irradiation. However, caution is warranted due to potential activation of trace contaminants, such as cobalt-59, which can become cobalt-60 and emit strong gamma radiation when irradiated. It is recommended to start with small samples of both materials and conduct short irradiation tests to monitor radioactivity levels. Utilizing a detector for gamma analysis can help identify any radioactive isotopes produced. If radioactivity levels become too high, waiting for decay is a viable option, as isotopes with higher activity typically have shorter half-lives.