Mapping of the magnetic field to correct systematic effects in a neutron electric dipole moment experiment

C. Abel , N.J. Ayres , G. Ban (1) , G. Bison , K. Bodek , V. Bondar , E. Chanel , P.-J. Chiu , B. Clément (2) , C.B. Crawford , M. Daum , S. Emmenegger , L. Ferraris-Bouchez (2) , M. Fertl , P. Flaux (1) , A. Fratangelo , W.C. Griffith , Z.D. Grujić , P.G. Harris , L. Hayen , N. Hild , M. Kasprzak , K. Kirch , P. Knowles , H.-C. Koch , P.A. Koss , A. Kozela , J. Krempel , B. Lauss , T. Lefort (1) , Y. Lemière (1) , P. Mohanmurthy , O. Naviliat-Cuncic (1) , D. Pais , F.M. Piegsa , G. Pignol (2) , P.N. Prashanth , G. Quéméner (1) , M. Rawlik , D. Ries , D. Rebreyend (2) , S. Roccia (2, 3) , D. Rozpedzik , P. Schmidt-Wellenburg , A. Schnabel , N. Severijns , J.A. Thorne , R. Virot (2) , A. Weis , E. Wursten , G. Wyszynski , J. Zejma , G. Zsigmond

1 LPCC - Laboratoire de physique corpusculaire de Caen
2 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
3 ILL - Institut Laue-Langevin

Experiments dedicated to the measurement of the electric dipole moment of the neutron require outstanding control of the magnetic-field uniformity. The neutron electric dipole moment (nEDM) experiment at the Paul Scherrer Institute uses a ${}^{199}\mathrm{Hg}$ co-magnetometer to precisely monitor temporal magnetic-field variations. This co-magnetometer, in the presence of field nonuniformity, is, however, responsible for the largest systematic effect of this measurement. To evaluate and correct that effect, offline measurements of the field nonuniformity were performed during mapping campaigns in 2013, 2014, and 2017. We present the results of these campaigns, and the improvement the correction of this effect brings to the neutron electric dipole moment measurement.

Mots clés: n: electric moment; magnetic field: spatial distribution; measurement methods; mercury

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Physique des Hautes Energies - Expérience [hep-ex]; Physique Nucléaire Expérimentale [nucl-ex]

C. Abel, N.J. Ayres, G. Ban, G. Bison, K. Bodek, et al.. Mapping of the magnetic field to correct systematic effects in a neutron electric dipole moment experiment. Phys.Rev.A, 2022, 106 (3), pp.032808. ⟨10.1103/PhysRevA.106.032808⟩. ⟨hal-03186175⟩