高橋睦郎の世界/The World of Mutsuo Takahashi

要旨 本稿は、日本現代詩を代表する詩人高橋睦郎をとりあげ、初期の作品から今日に至るまでの作品について、樹木のモチーフの変化を分析する。父の早世など、過酷な幼児期は、自叙伝的な家庭史と神話を絡ませた円環形式をもつ詩集『姉の島』(1995) に結晶した。だが、2000年以降は、環境破壊、家族崩壊、テロなどの社会問題など、外の世界へと向かっていく。社会的なテーマは、日本の詩歌では歴史が浅いが、逆説的なレトリックによって、高橋睦郎は多義的で抒情的な思想詩を生み出した。東北地方太平洋沖大震災のあった2011年以降の作品は、核エネルギーの問題、情報化時代を背景とした言語の空洞化を主題として新しい展開を見せている。 AbstractThis paper presents the poetry of Mutsuo Takahashi, one of the most important contemporary Japanese poets. We particularly focus on analysing the tree motif in the poems created since the poets’ early stages to the present day. The collection of poetry Sister’s Islands (1995), inspired by the poet’s childhood, full of tragic events such as his father’s premature death and his mother’s abandonment of him, interweaves autobiographical and mythological elements in a ringlike structure. However, after the year 2000 a new creative phase in his work ensued, wherein the poet deals with the problems facing our world such as ecological issues, disintegration of the family, terrorism, etc. The poems created after the great earthquake in Tohoku in 2011 open up new topics such as the ecological catastrophe caused by nuclear energy, loss of the meaning of words in the contemporary era, when information is exchanged at a lightning speed.

Energy losses of ions implanted in matter

A set of simple and accurate formulae for the first four moments of nuclear and electronic energy losses is proposed. A new variable is introduced to include the finite maximum-impact-parameter effect in the nuclear stopping process, which is assumed to be infinite in most studies. A critical energy at which the electronic energy loss is equal to the nuclear energy loss is also defined. It determines whether the nuclear or the electronic stopping process is the dominant mechanism in terms of incident-ion energy. The critical energy increases for heavy ions implanted in heavy target materials during the first moment of energy loss. The second moment of electronic energy loss is important only for light ions implanted at high ion energies. The third and fourth moments of nuclear energy loss are much larger than those of the electronic energy loss for all ion-target combinations. Theoretical predications of the projected ranges and range stragglings for gold ions implanted in carbon films are close to the experimental data when these proposed four moments of nuclear and electronic energy losses are considered.