TY - JOUR
T1 - The scattering of slow neutrons by <em>ortho</em>- and <em>para</em>-hydrogen
JF - Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences
JO - Proc R Soc Lond A Math Phys Sci
SP - 19
LP - 32
M3 - 10.1098/rspa.1955.0110
VL - 230
IS - 1180
AU -
AU -
Y1 - 1955/06/12
UR - http://rspa.royalsocietypublishing.org/content/230/1180/19.abstract
N2 - The neutron velocity selector of the Cavendish Laboratory has been used to measure the scattering cross-sections of ortho- and para-hydrogen for slow neutrons. The triplet and singlet scattering amplitudes of the neutron-proton interaction may be deduced from these cross-sections. The values obtained are at = (0·537 ± 0·004) x 10-12 cm, as = -(2·373 ±0·007) x 10-12 cm, where at and as are the triplet and singlet scattering amplitudes respectively. The values of the coherent scattering amplitude ƒ = 2(3/4a+1/4a), and of the free proton cross-section σƒ= 4π(3/4a2t + 1/4a2s given by the above values of at and as, are ƒ = -(0·380 ± 0·005) x 10-12 cm, σƒ= (20·41 ± 0·14) x 10-24 cm2.
ER -