# Task Introduction

In this task you will use OpenMC to simulate time-resolved neutron detection. The examples demonstrate how to use time filters to tally neutron interactions as a function of time, which is relevant for modelling pulsed neutron sources, time-of-flight measurements, and detector response studies.

The examples progress from a simple time-filtered tally, to including reflective boundary conditions that allow neutrons to bounce and be detected at later times, and finally to combining time and energy filters for a more detailed detector response.

**Learning Outcomes**

- Time filters can be applied to tallies to resolve neutron interactions as a function of time after a pulse.
- Reflective boundaries cause neutrons to persist in the system, producing signals at later times.
- Time and energy filters can be combined to produce time-energy resolved spectra, similar to time-of-flight detector measurements.