丙氨酸-ESR剂量计用于测量产品箱内剂量分布的研究

本文用自制丙氨酸-ESR剂量计和西德辐射与环境研究中心(GSF)的丙氨酸-ESR剂量计,测量了北京市射线应用中心的~(60)Coγ辐射源(1.44×10~(16)Bq)辐照纸箱包装(913mm×555mm×460mm)产品箱时的吸收剂量分布,箱内模拟产品(报纸)的堆积密度为200ks/m~3,测量结果表明,产品箱內最大剂量D_(max)与最小剂量D_(min)之比分别为1.45(北京市辐射中心)和1.47(GSF),两者相差1.40％,在允许误差范围之内。     

重铬酸盐剂量计在食品辐照加工中的应用

重铬酸盐剂量计是国内食品辐照加工行业普遍使用的一种液体化学剂量计。介绍了其工作原理、组成、校准过程等,并简要阐述了重铬酸盐剂量计在食品辐照加工确认和加工控制中的应用,为其今后在国内食品辐照加工中的广泛应用提供参考。     

醉蟹辐照剂量处理的研究

辐射在介质中产生的效应直接依赖于所吸收的辐射能量。为保证“醉蟹辐照保质”项目实施 ,本文从剂量计配制、放取样品位置、辐照时间确定、辐照样品不均匀度、剂量计比对等方面进行了探讨 ,为商业化醉蟹辐照提供一定的参考数据     

Calibrating the pesticide capture efficiency of passive dosimeters

A system has been devised for determining the absolute capture efficiency of passive dosimeters. The system is composed of three components: a wind tunnel, a tracer atomizer, and a capture efficiency test device (CETD). The CETD consists of a series of cylinders separated by nylon screens to intercept and capture the spray containing a tracer. The decline in tracer at the screens was used to determine the tracer incident on the first screen. This in turn was used to estimate the tracer incident on a test dosimeter of washed muslin. The capture efficiency of the dosimeter was expressed as the ratio of tracer captured to tracer incident on the dosimeter. The capture efficiency of the test dosimeter using the CETD was found to be independent of the time of exposure and quantity of tracer captured. The approach presented is novel in that the method for documenting capture efficiency does not require prior knowledge of the spray concentration. Elimination of this requirement allows the use of the device in a much larger array of test situations (e.g. field and greenhouse studies) than has been previously possible. Furthermore, the conceptual model can easily be modified to allow for capture efficiency measurements from a range of structures and materials such as plants or whole leaves, as well as insects and non-target animal species. The CETD is simple and portable and could be used to calibrate dosimeters in a variety of field situations.     

Implementation of total body photon irradiation as part of an institutional bone marrow transplant program for the treatment of canine lymphoma and leukemias

A total body irradiation (TBI) protocol was developed to support a bone marrow transplant (BMT) program for the treatment of canine hematologic malignancies. The purpose of this prospective study is to describe implementation of the protocol and resultant dosimetry. Nongraphic manual treatment planning using 6 MV photons, isocentric delivery, 40 × 40 cm field size, wall‐mounted lasers to verify positioning, a lucite beam spoiler (without use of bolus material), a dose rate of 8.75 cGy/min at patient isocenter, and a source‐to‐axis distance of 338 cm were used for TBI. A monitor unit calculation formula was derived using ion chamber measurements and a solid water phantom. Five thermoluminescent dosimeters (TLDs) were used at various anatomic locations in each of four cadaver dogs, to verify fidelity of the monitor unit formula prior to clinical implementation. In vivo dosimetric data were then collected with five TLDs at various anatomic locations in six patients treated with TBI. A total dose of 10 Gy divided into two 5 Gy fractions was delivered approximately 16 h apart, immediately followed by autologous stem cell transplant. The mean difference between prescribed and delivered doses ranged from 99% to 109% for various sites in cadavers, and from 83% to 121% in clinical patients. The mean total body dose in cadavers and clinical patients when whole body dose was estimated by averaging doses measured by variably placed TLDs ranged from 98% to 108% and 93% to 102% of the prescribed dose, respectively, which was considered acceptable. This protocol could be used for institutional implementation of TBI.     

中药辐照剂量分布的测量与计算

利用重铬酸银剂量计对以静态堆码方式进行辐照的某中药中的剂量分布进行测量,并利用蒙特卡罗方法进行了相应的模拟计算。计算结果表明统计误差在5%以内,计算值和实测值的相对偏差在20%以内,计算结果基本反映了该剂量分布的真实情况。