Progress on the CeNTREX TlF Schiff moment search

The aim of CeNTREX (Cold molecule Nuclear Time-Reversal Experiment) is to search for the proton’s electric dipole moment by measuring the Schiff moment it induces in the ²⁰⁵Tl nucleus. We use the amplified energy shift from the Schiff moment that is present in the polar molecule thallium fluoride (TlF). To maximize the population of the science state, we employ rotational cooling on the cold TlF beam, which pumps lowest few rotational states into a single J=0 hyperfine level of the ¹Σ⁺ electronic ground state. Electrostatic focusing with a quadrupole lens will be used to efficiently direct molecules to a downstream detection region; this requires a weak-field seeking state. This is achieved by adiabatic state transfer from J=0 to J=2 with microwaves. Finally, the Schiff moment measurement requires careful nulling of magnetic fields in the interaction region. Characterization of a new magnetic shielding system is ongoing.