Design and construction of a dose calibrator for measuring activity of radioisotopes

Abstract

It is necessary to know the exact value of radioisotope activity in the field of radio-pharmaceutical therapy or diagnostic applications. Dose calibrators are usually utilized in the nuclear medical centers for this purpose. Because of the sophisticated technology used in dose calibrators and due to the limited demand, only a few American and European companies supply the dose calibrators, thereby, the very high prices, a dose calibrator makes it uneconomical for the medical centers to purchase. This paper introduces a brief description of the design and construction of a dose calibrator along with an assessment of a thorough experiment results. The detector of the dose calibrator is a chamber that works in the current mode. The ionization area of the chamber has two cylinder spaces filled with argon gas. The electrometer of this system has been designed in a way that it can measure very low currents of a few femtoamperes (10-15 A). The results of experiments and practitioners’ reports showed that the device is able to measure the activity of γ and β sources with high accuracy in a wide range. Measuring low activities, having high accuracy, low cost, and being user friendly are some advantages of this device.

Keywords

• dose calibrator
• activity
• calibration