Gel forming composition for radiation dosimetry and radiation dosimeter using gel that is formed from said composition

A gel forming composition for radiation dosimetry comprising a gelator and a compound of Formula (1):

• wherein R1 is a hydrogen atom, a halogen atom, an optionally substituted C1-12 alkyl group, an optionally substituted C1-12 alkyloxy group, an optionally substituted C1-12 alkylthio group, an optionally substituted monovalent C6-12 aromatic group, or a monovalent C3-12 heteroaromatic group having at least one of a nitrogen atom, an oxygen atom, or a sulfur atom as a ring atom;
• and
• R2 and R3 are each independently a hydrogen atom, an optionally substituted C1-12 alkyl group, an optionally substituted monovalent C6-12 aromatic group, or a monovalent C3-12 heteroaromatic group having at least one of a nitrogen atom, an oxygen atom, or a sulfur atom as a ring atom, or R2 and R3 form a 4- to 8-membered ring together with a carbon atom to which R2 and R3 are bonded, and the 4- to 8-membered ring optionally has 0 to 3 nitrogen atoms, oxygen atoms, or sulfur atoms as a ring atom, provided that R2 and R3 are not simultaneously a hydrogen atom, and
• wherein the gelator contains a water-soluble organic polymer (A) having an organic acid structure, an organic acid salt structure, or an organic acid anion structure, a silicate (B), and a dispersant (C) for the silicate.