Masatoshi Koshiba

Masatoshi Koshiba (小柴 昌俊, Koshiba Masatoshi; 19 September 1926 – 12 November 2020) was a Japanese physicist and one of the founders of neutrino astronomy. His work with the neutrino detectors Kamiokande and Super-Kamiokande was instrumental in detecting solar neutrinos, providing experimental evidence for the solar neutrino problem.

Koshiba ya lashe kyautar Nobel a fannin kimiyyar lissafi a shekarar 2002, tare da Raymond Davis Jr., "saboda gudummawar da ya bayar ga ilmin taurari, musamman gano ƙwayoyin neutrinos na sararin samaniya". Koshiba shi ne mutum na farko da ya lashe kyautar Nobel ta Japan da ya riƙe digirin digirgir biyu. Bugu da ƙari, shi ne mutum na biyu da ya karɓi kyautar Nobel da kyautar Wolf a Japan. Malaminsa, Sin-Itiro Tomonaga, da ɗalibinsa, Takaaki Kajita, suma sun lashe kyautar Nobel a fannin kimiyyar lissafi.Koshiba ya lashe kyautar Nobel a fannin kimiyyar lissafi a shekarar 2002, tare da Raymond Davis Jr., "saboda gudummawar da ya bayar ga ilmin taurari, musamman gano ƙwayoyin neutrinos na sararin samaniya". Koshiba shi ne mutum na farko da ya lashe kyautar Nobel ta Japan da ya riƙe digirin digirgir biyu. Bugu da ƙari, shi ne mutum na biyu da ya karɓi kyautar Nobel da kyautar Wolf a Japan. Malaminsa, Sin-Itiro Tomonaga, da ɗalibinsa, Takaaki Kajita, suma sun lashe kyautar Nobel a fannin kimiyyar lissafi.

Ya kasance babban mai ba da shawara a Cibiyar Nazarin Fizik ta Ƙasa da Ƙasa (ICEPP) kuma farfesa a Jami'ar Tokyo.

 Rayuwar farko 
An haifi Koshiba a Toyohashi da ke tsakiyar Japan a ranar 19 ga Satumba, 1926, ga Toshio da Hayako Koshiba. Mahaifinsa jami'in soja ne. Mahaifiyarsa ta mutu yana ɗan shekara uku, wanda hakan ya sa mahaifinsa ya auri babbar 'yar uwar matarsa.  Ya girma a Yokosuka, kuma ya kammala makarantar sakandare a Tokyo . An ambaci cewa sha'awarsa ta farko ita ce nazarin adabin Jamusanci, amma, ya ƙare da karatun kimiyyar lissafi, sakamakon kalaman ɓatanci na malami. 

Ya kammala karatunsa daga Jami'ar Tokyo a shekarar 1951 kuma ya sami digirin digirgir a fannin kimiyyar lissafi daga Jami'ar Rochester, New York, a shekarar 1955.  

 Aiki da bincike 
Koshiba ya fara aikinsa a matsayin mai bincike a Sashen Lissafi na Jami'ar Chicago daga Yuli 1955 zuwa Fabrairu 1958, kuma farfesa ne a Cibiyar Nazarin Nukiliya, Jami'ar Tokyo daga Maris 1958 zuwa Oktoba 1963. Yayin da yake hutu daga Nuwamba 1959 zuwa Agusta 1962, ya yi aiki a matsayin darakta mai rikon kwarya, Dakin gwaje-gwaje na Kimiyyar Makamashi Mai Kyau da Hasken Radiation na Cosmic, Sashen Lissafi na Jami'ar Chicago.  

A Jami'ar Tokyo ya zama mataimakin farfesa a watan Maris na 1963 sannan ya zama farfesa a watan Maris na 1970 a Sashen Lissafi, Faculty of Science, sannan kuma farfesa na emeritus a can a shekarar 1987. Daga 1987 zuwa 1997, Koshiba ya koyar a Jami'ar Tokai . 

A shekara ta 2002, ya lashe kyautar Nobel a fannin kimiyyar lissafi tare da "gudummawar da ya bayar ga fannin ilmin taurari, musamman gano ƙwayoyin halitta na sararin samaniya". (Sauran hannun jari na wannan shekarar an ba su ga Raymond Davis Jr. da Riccardo Giacconi na Amurka) 

Binciken farko na Koshiba ya kasance a cikin haskoki na sararin samaniya. A shekarar 1969, ya koma fannin kimiyyar hada-hadar electron-positron, kuma ya shiga cikin na'urar gano JADE a Jamus, wanda ya taimaka wajen tabbatar da Tsarin Daidaitacce. Tare da Masayuki Nakahata da Atsuto Suzuki, Koshiba ya tsara gwajin Kamiokande don gano ruɓewar proton, wani hasashen manyan ka'idoji masu haɗin kai . Ba a gano ruɓewar proton ba, amma Koshiba ya fahimci cewa za a iya yin na'urar gano neutrinos, kuma ya daidaita aikin daidai gwargwado, bayan aikin farko na Davis na Amurka.

Manazarta 

Rukuni:Mutattun 2020
Rukuni:Haifaffun 1926