相关论文: Bright, continuous beams of cold free radicals
We propose to sympathetically slow and cool polar molecules in a cold, low-density beam using laser-cooled Rydberg atoms. The elastic collision cross sections between molecules and Rydberg atoms are large enough to efficiently thermalize…
High precision spectroscopy on the $2 \ ^3 S \rightarrow 2 \ ^1 S$ transition is possible in ultracold optically trapped helium but the accuracy is limited by the ac-Stark shift induced by the optical dipole trap. To overcome this problem,…
A high-intensity supersonic beam source has been a key component in studies of molecular collisions, molecule-surface interaction, chemical reactions, and precision spectroscopy. However, the molecular density available for experiments in a…
X-rays have widespread applications in science and industry, but developing a simple, compact, and high-quality X-ray source remains a challenge. Our collaboration has explored the possible use of channeling radiation driven by a 50 MeV…
Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of…
Over the last decades, significant advances in high-power laser systems have enabled rapid progress in the development of laser-driven plasma accelerators. Today, the results obtained in beam stability and reproducibility present laser…
Bose-Einstein condensates (BECs) of neutral atoms constitute an important quantum system for fundamental research and precision metrology. Many applications require short preparation times of BECs, for example, for optimized data…
The quantum mechanical nature of spherical top molecules is particularly evident at low angular momentum quantum number J. Using infrared spectroscopy on the 8.4$\mu$m rovibrational band of buffer gas cooled $^{12}$C$_{60}$, we observe the…
Direct laser cooling of molecules has made significant progress in recent years. However, the selective cooling and manipulation of molecules based on their isotopic composition, which is ubiquitous in atomic laser cooling, has not yet been…
One of the prominent platforms for quantum technologies, cold atoms require reliable laser systems. We present the design, implementation, and characterization of a simple, compact, and economical laser system at 780 nm, entirely based on…
The continuous development of bright x/gamma-ray sources has opened up new frontiers of science and advanced applications. Currently, there is still a lack of efficient approaches to produce gamma-rays with photon energies up to GeV and…
Cryogenic transmission electron microscopy has revolutionized structural biology and materials science, but achieving temperatures below the boiling point of liquid nitrogen remains a long-standing aspiration. We introduce an ultra-cold…
A molecular-dynamics thermal annealing model is proposed to investigate the mechanisms involved in picosecond pulsed laser ablation of crystalline silicon. In accordance with the thermal annealing model, a detailed description of the…
We describe a helium evaporation refrigerator used to cool dynamically polarized proton and deuteron targets for electron-scattering experiments using the CEBAF Large Acceptance Spectrometer CLAS12 at Jefferson Lab. The geometry of the…
Multi-phase filamentary structures around Brightest Cluster Galaxies are likely a key step of AGN-feedback. We observed molecular gas in 3 cool cluster cores: Centaurus, Abell S1101, and RXJ1539.5 and gathered ALMA and MUSE data for 12…
We demonstrate the direct loading of a D$_2$ MOT of potassium-39 atoms from a cryogenic buffer gas beam source. We load $10^8$ atoms in a 10 ms pulse, with no degradation in performance up to a 10 Hz repetition rate. Observed densities…
The baryonic content and physical properties of the warm and hot ($10^5\lesssim T\lesssim 10^7$ K) phases of the circumgalactic medium (CGM) are poorly constrained, owing to the lack of observables probing the requisite range of…
We present a simple, robust, narrow-linewidth, frequency-doubled semiconductor laser source suitable for laser cooling and repumping of $^9$Be$^+$ ions. A distributed Bragg reflector (DBR) laser diode operating at 626 nm is…
It has been roughly three decades since laser cooling techniques produced ultracold atoms, leading to rapid advances in a vast array of fields. Unfortunately laser cooling has not yet been extended to molecules because of their complex…
We have produced a cryogenic buffer-gas cooled beam of the diatomic molecular radical CH (methylidyne). This molecule is of interest for studying cold chemical reactions and fundamental physics measurements. Its light mass and ground-state…