Ion loading and cooling

A complete ion-loading routine from laser ablation to fluorescence detection, using Quatm’s multi-stage timing control.

Overview

This script provides the class loading_ion: it orchestrates the complete ion-loading routine from switching on the RF trap, producing ions by ablation and laser cooling through to fluorescence detection. The number of ablation pulses, the pulse width and the cooling/detection durations are all GUI parameters.

Parameters (build excerpt)

Nr_Ablation_Pulses, tune_pulse_number, pulse_duration, det_time, shutter_time, V_rf (trap voltage), ion_cool_power.

Timing

Switch on the RF trap (V_rf) → ablation pulses (several) → laser cooling
  → fluorescence detection (count to decide whether the ion loaded successfully)

Key code (excerpt)

from quatm.experiment import Experiment

class loading_ion(Experiment):
    def build(self):
        self.setattr_argument("Nr_Ablation_Pulses", NumberValue(...))
        self.setattr_argument("V_rf", NumberValue(...))
        # ... remainder omitted

ablation_pulse.py (single ablation), deterministic_loading.py and loading_deterministic.py (deterministic loading: retry on failure).

Companion

The cooling and fluorescence counting after ion loading can be combined with quantum-state detection for state-dependent measurements; the default parameters of the RF trap are in rf_trap.py.