Theoretical study of the measurement of electric field strength based on the pendular spectra of linear (HCCCN)_n (n = 1−3) molecules

The pendular spectra of linear (HCCCN)_n (n = 1−3) molecules at several rotational temperatures under a certain range of electric field strength E are calculated using the finite element matrix diagonalization method. In addition, the normalized “Q-branch” intensity (I_Q) and the gradient (K_E ) of I_Q under corresponding conditions are investigated. Based on the results, the range and sensitivity of measuring the electric field strength with linear (HCCCN)_n (n = 1 − 3) molecules are analyzed. A scheme to measure electric field strength based on (HCCCN)_n (n = 1 − 3) with high sensitivity is proposed and the spatial resolution is also discussed. The feasibility of measuring the electric field strength of the electrostatic Stark decelerator based on a pendular spectrum is studied.