Wiederholungsintervalle

Could you please confirm the full term after "Wiederholungsi"? The segment "Wiederholungsi..." could refer to several different German terms or concepts (for example, a word starting with "Wiederholungsi-" or a specific noun in a particular field). Providing the exact word or the intended topic (and its domain) will help me write a precise, neutral wiki-style article under 300 words.