# 17th International Conference on Ion Sources

15-20 October 2017
CERN
Europe/Zurich timezone

## Efficient Method for Cold Muonium Negative Ion Production

16 Oct 2017, 16:30
2h 30m
CERN

#### CERN

Centre international de Conférence Genève (CICG). http://www.cicg.ch/
Poster presentation Negative ion sources

### Description

Charged muons as Muonium negative ions (consisting of positive Mu ¬ meson and 2 electrons) have affinity S=0.75 eV. Muonium have ionization energy I=13.6 eV. Muonium negative ions were observed in 1987 [1], [2] by interaction of muons with a foil. In this work an efficiency of transformation of Mu mesons to negative muonium ions were very low 10-4. However, with using tungsten or palladium single crystal with deposition cesium it can be improved up to 40-50%.
A new, efficient method to produce cold negative muon ions is proposed, where surface muons are focused onto a tungsten or palladium single crystal foil (with a possibility to heat up to 2000$^{\circ}$ C) and partially covered by a cesium layer up to minimal work function. The negative muon ions can be extracted by a DC electric field and further accelerated by a linac and stripped in a thin foil.

References

[1] Y. Kuang, K.-P. Arnold, F. Chmely, et. al., “First observation of the negative muonium ion produced by electron capture in a beam-foil experiment”, PHYSICAL REVIEW ,V.35, 3172 (1987).

[2] Y. Kuang, K.-P. Arnold, and F. Chmely, et. al., “Formation of the negative muonium ion and charge-exchange processes for positive muons passing through thin metal foils”, Phys. Rev. A, general physics, THIRD SERIES, VOLUME 39, NUMBER 12, 6109 (1989).

### Presentation materials

 Cold_Muonium efficient.pdf T4_Mo_75 muonium negative ions1.docx T4_Mo_75 muonium negative ions1.pdf