A new source-preparation technique of uranium phosphate conversion coating was developed for the determination of uranium isotope ratio by alpha spectrometry. It was found experimentally that under the conditions of 3.14 cm2 Ni-foil,0.5 mol/L HCl,2.5 mol/L NaCl ,0.08 mol/L KH 2 PO 4 ,20 g/L ascorbic acid ,25 mL initial solution,90℃ constant experiment temperature,1 60 r/min vibration frequency ,20 mm vibration amplitude,and 70min deposition time ,uranium less than 200 μg can be quantitatively and spontaneously converted into phosphorization film on Ni-foil. Compared to the tradi-tional source-preparation technique of electro-deposition,the technique of uranium phosphate conversion coating has the advantage of simple in electro-deposition device, easy in operation, high working-efficiency ,no interference in measuring lots of coexisting radionuclides such as 2 3 2 Th ,2 30 Th,22 6 Ra,2 3 1 Pa and so on in phosphating solution. The total spike recovery rate of uranium reaches 100% nearly,and the spectrum resolution is good in determing uranium isotope ratio by alpha spectrometry.%研发了一种用于铀同位素比值α能谱分析的磷化膜制源新技术.试验发现,当镍镀片面积为3.14 cm2,盐酸浓度为0.5 mol/L ,氯化钠浓度为2.5 mol/L ,磷酸二氢钾浓度为0.08 mol/L,抗坏血酸浓度为20 g/L,溶液体积为25 mL,恒温90℃,振荡速率为160次/min,振程20 mm 时,磷化膜制源70 min,200μg 以下的铀可在镍箔上定量转化为磷化膜.与传统的电沉积制源技术相比较,应用磷化膜制源技术进行测量源制备时无需电沉积装置,制源过程简单快速,工效高,大量共存的232 Th 、230 Th、226 Ra、231 Pa 等核素均不产生干扰,铀的全程回收率接近100％,α能谱峰分辨率较好.
展开▼
