ESR RESPONSE TO 60 CO-RAYS OF AMMONIUM TARTRATE PELLETS USING GD2O3 AS ADDITIVE.

This work presents experimental results regarding a new ammonium tartrate blend for ESR dosimetry, with a higher sensitivity and a lower lowest detectable dose (LDD) to 60 Co -rays than the recently used pure ammonium tartrate. The blend composed by ammonium tartrate and gadolinium-oxide (Gd2 O3 ) shows a greater sensitivity (∼2 times) and a smaller LDD than ammonium tartrate. The increased sensitivity was mainly attributed to the great atomic number (Z = 64) of gadolinium, that increases the effective atomic number of the blend; the interaction probability with photons and consequently the radical yield is therefore enhanced. Moreover ammonium tartrate with Gd2 O3 has a linear dose response in the investigated dose range (1–50 Gy). We find this blend suitable for use in ESR dosimetry.