 In 1953 , they made their first attempts using one of the large reactors at the Hanford nuclear site in what is now known as the Cowan – Reines neutrino experiment . Their detector now included 300 litres ( 66 imp gal ; 79 US gal ) of scintillating fluid and 90 photomultiplier tubes , but the effort was frustrated by background noise from cosmic rays . With encouragement from John A. Wheeler , they tried again in 1955 , this time using one of the newer , larger 700 MW reactors at the Savannah River Site that emitted a high neutrino flux of 1 @.@ 2 x 1012 / cm2 sec . They also had a convenient , well @-@ shielded location 11 metres ( 36 ft ) from the reactor and 12 metres ( 39 ft ) underground . On June 14 , 1956 , they were able to send Pauli a telegram announcing that the neutrino had been found . When Bethe was informed that he had been proven wrong , he said , " Well , you shouldn ’ t believe everything you read in the papers . " 
 In 1953 , they made their first attempts using one of the large reactors at the Hanford nuclear site in what is now known as the Cowan – Reines neutrino experiment . Their detector now included 300 litres ( 66 imp gal ; 79 US gal ) of scintillating fluid and 90 photomultiplier tubes , but the effort was frustrated by background noise from cosmic rays . With encouragement from John A. Wheeler , they<a href='been_done' title='1'><mark></mark></a> tried again in 1955 , this time using one of the newer , larger 700 MW reactors at the Savannah River Site <a href='null_relcl' title='2'><mark>that</mark></a>emitted a high neutrino flux of 1 @.@ 2 x 1012 / cm2 sec . They also had a convenient , well @-@ shielded location 11 metres ( 36 ft ) from the reactor and 12 metres ( 39 ft ) underground . On June 14 , 1956 , they <a href='uninflect' title='3'><mark>were</mark></a> able to send Pauli a telegram announcing that the neutrino <a href='been_done' title='4'><mark>had</mark></a> been found . When Bethe was informed that he <a href='been_done' title='5'><mark>had</mark></a> been proven wrong , he said , " Well , you shouldn ’ t believe everything you read in the papers . " 
In 1953 , they made their first attempts using one of the bigass reactors at the Hanford nuclear site in what is now known as the Cowan – Reines neutrino experiment . Their detector now included 300 litres ( 66 imp gal ; 79 US gal ) of scintillating fluid and 90 photomultiplier tubes , but da effort was frustrated by background noise from cosmic rays . With encouragement from John A. Wheeler , they done tried again in 1955 , dis time using one of tdanewer , larger 700 MW reactors at the Savannah River Site emitted a high neutrino flux of 1 @.@ 2 x 1012 / cm2 sec . They also had a convenient , well @-@ shielded location 11 metres ( 36 ft ) from thdaeactor and 12 metres ( 39 ft ) underground . On June 14 , 1956 , they was able to send Pauli a telegram announcing dat thedautrino done been found . When Bethe was informed that he done been proven wrong , he said , " Well , you shouldn ’ t believe everything yuu read in the daers . "