The Fifth Conference “ N uclear Science and Its A pplication”, 14-17 O ctober 2008
COMPLEX
OF
EQUIPMENT
FOR
PREPARATION
OF
HIGH-
QUALITY RADIOACTIVE SOURCES USED IN PRECISE NUCLEAR
SPECTROSCOPY
N.U.ALDIYAROV. K.K.KADYRZHANOV, V.S.ZHDANOV
The Institute o f Nuclear Physics under National Nuclear Center o f the Republic ofKazakhstan
Precise investigations o f spectra from nuclear radiations are quite sensitive to quality o f radiation sources used. In an ideal case a source should introduce no noticeable distortion into registered spectrum. In spectroscopy o f low-energy gam m a quanta, electrons and alpha particles sample preparation quite frequently turns to be a challenging independent scientific investigation. Source preparation is conventionally perform ed at two stages - extraction o f activity from a target and its uniform distribution over a substrate. A general requirem ent to such radioactive layer is m axim al total and specific activity.
The paper introduces a com plex o f experim ental equipm ent for preparation o f high-quality radioactive sources. This com plex is arranged in a w ell-protected h eav y box equipped w ith m aster- slave manipulators. B iological protection o f the box m akes it possible to handle activities up to 10 11 Bq, M ain part o f the com plex is a special vacuum post that assures w orks w ith active sam ples in the vacuum up to 10'7 m m Hg - the operations include fractional sublim ation, therm al evaporation, therm al diffusion, evaporation by electron beam , etc. A ll units o f the vacuum post arranged in the box are designed to w ork w ith m aster-slave m anipulators. T he p o st is m ainly u sed for preparation o f a high-quality beta sources and extraction o f m icroam ounts o f radionuclides from reactor and cyclotron targets by the m ethod o f fractional sublimation. A nother im portant unit o f the com plex is an equipm ent for selective chem iosorption in vacuum . C om plex com prises all required auxiliary equipm ent. The entire com plex operated at high rate o f reliability.
The paper pays particular attention both to system atization o f available data on application o f fractional sublim ation and to consideration o f a range o f im portant issues regarding the m echanism o f this process in order to optim ize the procedures for preparation o f radioactive sources for precise nuclear spectroscopy. E m ploying the m ethod o f fractional sublim ation at the com plex there w ere produced the follow ing high-quality sources: 101Pd, !05,106-ulA g, 107-m Cd, 131J, 131>i36Cs, 194A u and 209,210,211 At. The w orks on obtaining highly active sources for m easurem ents o f im portant low- intensity spectra o f three-electron A uger transitions are in progress [1].
1. M .I.Babenkov, K .K .K adyrzhanov, V.S.Zhdanov // LIE! International M eeting N U C LE U S- 2003” . 2003, P.253 (in Russion).