Bright, continuous beams of cold free radicals
| Autor: | J. C. Shaw, D. J. McCarron |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Laser ablation Atomic Physics (physics.atom-ph) Liquid helium Buffer gas FOS: Physical sciences Steradian chemistry.chemical_element Rotational temperature 01 natural sciences Physics - Atomic Physics 010305 fluids & plasmas law.invention chemistry law 0103 physical sciences Physics::Accelerator Physics Atomic physics 010306 general physics Molecular beam Beam (structure) Helium |
| Zdroj: | Physical Review A. 102 |
| ISSN: | 2469-9934 2469-9926 |
| DOI: | 10.1103/physreva.102.041302 |
| Popis: | We demonstrate a cryogenic buffer gas-cooled molecular beam source capable of producing bright, continuous beams of cold and slow free radicals via laser ablation over durations of up to 60~seconds. The source design uses a closed liquid helium reservoir as a large thermal mass to minimize heating and ensure reproducible beam properties during operation. Under typical conditions, the source produces beams of our test species SrF, containing $5\times10^{12}~$molecules per steradian per second in the $X^{2}\Sigma(v=0, N=1)$ state with a rotational temperature of $1.0(2)~$K and a forward velocity of $140~$m/s. The beam properties are robust and unchanged for multiple cell geometries but depend critically on the helium buffer gas flow rate, which must be $\geq10~$ standard cubic centimeters per minute to produce bright, continuous beams of molecules for an ablation repetition rate of $55~$Hz. Comment: 5 pages, 4 figures |
| Databáze: | OpenAIRE |
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