Online chemical adsorption studies of Hg, Tl, and Pb on SiO and Au surfaces in preparation for chemical investigations on Cn, Nh, and Fl at TASCA

TASCAを用いたCn, Nh, Fl化学実験のためのHg, Tl, PbのSiO及びAu表面に対するオンライン化学吸着研究

Lens, L.*; Yakushev, A.*; Dllmann, Ch. E.*; 浅井 雅人  ; Ballof, J.*; Block, M.*; David, H. M.*; Despotopulos, J.*; Di Nitto, A.*; Eberhardt, K.*; Even, J.*; Gtz, M.*; Gtz, S.*; 羽場 宏光*; Harkness-Brennan, L.*; Heberger, F. P.*; Herzberg, R. D.*; Hoffmann, J.*; Hbner, A.*; Jger, E.*; Judson, D. S.*; Khuyagbaatar, J.*; Kindler, B.*; 小森 有希子*; Konki, J.*; Kratz, J. V.*; Krier, J.*; Kurz, N.*; Laatiaoui, M.*; Lahiri, S.*; Lommel, B.*; Maiti, M.*; Mistry, A. K.*; Mokry, C.*; Moody, K.*; 永目 諭一郎 ; Omtvedt, J. P.*; Papadakis, P.*; Pershina, V.*; Runke, J.*; Schdel, M.*; Scharrer, P.*; 佐藤 哲也   ; Shaughnessy, D.*; Schausten, B.*; Thrle-Pospiech, P.*; Trautmann, N.*; 塚田 和明  ; Uusitalo, J.*; Ward, A.*; Wegrzecki, M.*; Wiehl, N.*; Yakusheva, V.*

Lens, L.*; Yakushev, A.*; Dllmann, Ch. E.*; Asai, Masato; Ballof, J.*; Block, M.*; David, H. M.*; Despotopulos, J.*; Di Nitto, A.*; Eberhardt, K.*; Even, J.*; Gtz, M.*; Gtz, S.*; Haba, Hiromitsu*; Harkness-Brennan, L.*; Heberger, F. P.*; Herzberg, R. D.*; Hoffmann, J.*; Hbner, A.*; Jger, E.*; Judson, D. S.*; Khuyagbaatar, J.*; Kindler, B.*; Komori, Yukiko*; Konki, J.*; Kratz, J. V.*; Krier, J.*; Kurz, N.*; Laatiaoui, M.*; Lahiri, S.*; Lommel, B.*; Maiti, M.*; Mistry, A. K.*; Mokry, C.*; Moody, K.*; Nagame, Yuichiro; Omtvedt, J. P.*; Papadakis, P.*; Pershina, V.*; Runke, J.*; Schdel, M.*; Scharrer, P.*; Sato, Tetsuya; Shaughnessy, D.*; Schausten, B.*; Thrle-Pospiech, P.*; Trautmann, N.*; Tsukada, Kazuaki; Uusitalo, J.*; Ward, A.*; Wegrzecki, M.*; Wiehl, N.*; Yakusheva, V.*

半減期449秒の短寿命同位体を用いて、水銀(Hg), タリウム(Tl), 鉛(Pb)の単一原子レベルでのSiO及びAu表面への固体吸着挙動をオンライン気相実験により調べた。超重元素Cn, Nh, Flの吸着エンタルピー測定のためのモデル実験として実施した。短寿命同位体はドイツ重イオン研究所の反跳核分離装置TASCAを用いて生成・分離した。生成核はヘリウムガス中に捕集された後、SiOあるいはAuで表面を覆われたSi検出器で作製されたガスクロマトグラフィーカラムへと導入した。短寿命Tl及びPb同位体は室温においてSiO表面に吸着し、Si検出器で測定することに成功した。一方、HgはSiO表面には吸着せず、Au表面に吸着した。この結果より、本実験のセットアップを用いることで短寿命Hg, Tl, Pb同位体の吸着特性を調べることができると証明され、この手法がCn, Nh, Flの実験にも適用できることが確認された。

Online gas-solid adsorption studies with single atom quantities of Hg, Tl, and Pb on SiO and Au surfaces were carried out using short-lived radioisotopes with half-lives in the range of 4-49 s. This is a model study to measure adsorption enthalpies of superheavy elements Cn, Nh, and Fl. The short-lived isotopes were produced and separated by the gas-filled recoil separator TASCA at GSI. The products were stopped in He gas, and flushed into gas chromatography columns made of Si detectors whose surfaces were covered by SiO or Au. The short-lived Tl and Pb were successfully measured by the Si detectors with the SiO surface at room temperature. On the other hand, the Hg did not adsorb on the SiO surface, but adsorbed on the Au surface. The results demonstrated that the adsorption properties of short-lived Hg, Tl, and Pb could be studied with this setup, and that this method is applicable to the experiment for Cn, Nh, and Fl.