Total and differential cross sections of η-production in proton-deuteron fusion for excess energies between Q_η=13 MeV and Q_η=81 MeV

New data on both total and differential cross sections of the production of η mesons in proton-deuteron fusion to ^3He η in the excess energy region 13.6 MeV≤ Q_η≤ 80.9 MeV are presented. These data have been obtained with the WASA-at-COSY detector setup located at the Forschungszentrum Jülich, using a proton beam at 15 different beam momenta between p_p = 1.60 GeV/c and p_p = 1.74 GeV/c. While significant structure of the total cross section is observed in the energy region 20 MeV≲ Q_η≲ 60 MeV, a previously reported sharp variation around Q_η≈ 50 MeV cannot be confirmed. Angular distributions show the typical forward-peaking that was reported elsewhere. For the first time, it is possible to study the development of these angular distributions with rising excess energy over a large interval.