# Low-Energy Magnetic Radiation

## TL;DR

This paper identifies a low-energy magnetic radiation spike (LEMAR) in the strength function, explaining enhanced dipole strength observed experimentally, and predicts its impact on nucleosynthesis reaction rates.

## Contribution

It introduces the concept of LEMAR originating from statistical low-energy M1-transitions and predicts its occurrence in r-process nuclides around mass 132.

## Key findings

- LEMAR causes a 2.5-fold increase in reaction rates.
- Spectral function of LEMAR follows Planck's Law.
- Power law distribution of B(M1) values observed.

## Abstract

A pronounced spike at low energy in the strength function for magnetic radiation (LEMAR) is found by means of Shell Model calculations, which explains the experimentally observed enhancement of the dipole strength. LEMAR originates from statistical low-energy M1-transitions between many excited complex states. Re-coupling of the proton and neutron high-j orbitals generates the strong magnetic radiation. LEMAR is predicted for nuclides with $A\approx 132$ participating in the r-process of element synthesis. It increases the reaction rates by a factor of 2.5. The spectral function of LEMAR follows Planck's Law. A power law for the size distribution of the $B(M1)$ values are found.