# A model of an ion-proton radio pulsar polar cap

## TL;DR

This paper develops an ion-proton model for pulsar polar caps, providing detailed calculations of pulse profiles, nulling behavior, and emission mechanisms, including special cases like millisecond pulsars and PSR J2144-3933.

## Contribution

It introduces a comprehensive ion-proton theory with step-by-step calculations and analysis of nulls and emission pathways, extending to various pulsar types.

## Key findings

- Pulse-precursor profiles modeled successfully.
- Null length varies with neutron-star temperature.
- Model explains emission in exceptional pulsars.

## Abstract

A number of previous papers have developed an ion-proton theory of the pulsar polar cap. The basic equations summarizing this are given here with the results of sets of model step-to-step calculations of pulse-precursor profiles. The nature of step-to-step profile variations is described by calculated phase-resolved modulation indices. The conditions under which nulls are present in step sequences are analysed. The change of mean null length with neutron-star surface temperature shows a pathway ending in emission similar to the Rotating Radio Transients. The model accommodates exceptional pulsars, the millisecond pulsars (in principle), and the 8.5 s period PSR J2144-3933. These are considered separately and their emission mechanism discussed in some detail.