A quantitative approach to disjointly non-singular operators

We introduce and study some operational quantities which characterize the disjointly non-singular operators from a Banach lattice E to a Banach space Y when E is order continuous, and some other quantities which characterize the disjointly strictly singular operators for arbitrary E.

RESPONSE OF CURRENT PHOTON PERSONAL DOSEMETERS TO NEW OPERATIONAL QUANTITIES

The ICRU proposed new operational quantities, which are defined in close relation to effective dose and absorbed dose. Most of the current personal dosemeters were designed to measure personal dose equivalents. Because of differences between the new and old quantities, the existing dosemeters may not be ideal for measurements of the new quantities, personal dose, Hp, and absorbed dose in local skin, Dp local skin. For photon radiation sources, we investigated relative responses of the current personal dosemeters with respect to the measurement of the new quantities. Introduction of the new quantities into practice will require some changes in practical radiation protection. A recalibration of the current dosemeters will be essential for Hp measurements in higher photon energy region (>50 keV). For lower photon energies, a redesign of specific evaluation algorithms will be necessary. For purposes of Dp local skin measurements the dosemeters do not require any fundamental changes.

MEASUREMENT OF OPERATIONAL DOSIMETRY QUANTITIES FOR NUCLEAR MEDICINE STAFF

According to the ALARA principle, exposure to radiation should be reduced as low as reasonably achievable. This principle is very important in nuclear medicine (NM), and different investigations have been performed by establishing protocols and standards for staff protection. This study aims to measure the operational quantities, personal dose equivalent, Hp (10), Hp (0.07) and Hp (3) for NM staff in Shiraz hospitals, and comparison with dose limits. Two types of dosimeters, TLD-100 and GR-200, were used in this study. In the first step, the calibration of dosimeters was performed using different phantoms. Then, a group of dosimeters was prepared and used for 1 month on the heads, wrists and chests of the staff for measurement of Hp (3), Hp (0.07) and Hp (10), respectively. The obtained values of Hp (10) were compared with the results of their personal dosimetry, film badge. The results of this study show good consistency in the measurements using the two dosimeters.