ホウ素中性子捕獲療法のためのリチウムターゲット表面に合成したLi
Nの表面化学状態
Surficial chemical states of Li
N synthesized on lithium target for boron neutron capture therapy
石山 新太郎; 馬場 祐治
; 藤井 亮*; 中村 勝*; 今堀 良夫*
Ishiyama, Shintaro; Baba, Yuji; Fujii, Ryo*; Nakamura, Masaru*; Imahori, Yoshio*
ホウ素中性子捕獲治療法のためのリチウムターゲット表面に合成した蒸発防止用Li
N表面層のO及びCの表面汚染を低減するための1123Kまでの超真空加熱試験を実施した結果、主要な汚染要素であるH
O, Li化合物であるLiOH及びLi
CO
は1123Kまでの真空加熱による分解除去できることがわかった。
To remove high level of contaminants by O and C from Li
N surface for boron neutron capture therapy target, high temperature thermal desorption was conducted up to 1123 K in ultra high vacuum and the following results were derived; (1) During thermal desorption up to 1023 K, typical three peaks of vacuum pressure disturbance due to vaporization of contaminants were observed in vacuum pressure-temperature curve. (2) Over-layered contaminants with high melting temperature below 1023 K on Li
N surface is completely removed by high temperature thermal desorption up to 1123 K in ultra high vacuum. (3) From these desorption results, it is suggested that these contaminants corresponding to these vaporization peaks are H
O and Li compounds with high melting temperature below 1023 K, of which LiOH and Li
CO
were synthesized by decomposition process of Li
N with residual H
O and CO
in low temperature.