Cold collisions in a molecular synchrotron

Abstract

We study collisions between neutral, deuterated ammonia molecules (ND${}_3$) stored in a 50 cm diameter synchrotron and argon atoms in co-propagating supersonic beams. The advantages of using a synchrotron in collision studies are twofold: (i) By storing ammonia molecules many round-trips, the sensitivity to collisions is greatly enhanced; (ii) The collision partners move in the same direction as the stored molecules, resulting in low collision energies. We tune the collision energy in three different ways: by varying the velocity of the stored ammonia packets, by varying the temperature of the pulsed valve that releases the argon atoms, and by varying the timing between the supersonic argon beam and the stored ammonia packets. These give consistent results. We determine the relative, total, integrated cross-section for ${\mathrm{ND}}_3+\mathrm{Ar}$ collisions in the energy range of 40-140 cm${}^{-1}$, with a resolution of 5-10 cm${}^{-1}$ and an uncertainty of 7-15%. Our measurements are in good agreement with theoretical scattering calculations.

References in corpus (12)

• The Buffer Gas Beam: An Intense, Cold, and Slow Source for Atoms and Molecules
• Observation of Quantum Effects in sub Kelvin Cold Reactions
• Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes
• Specific chemical reactivities of spatially separated 3-aminophenol conformers with cold Ca${}^{+}$ ions
• Imaging resonances in low-energy NO-He inelastic collisions
• Quantum-state resolved bimolecular collisions of velocity-controlled OH with NO radicals
• Direct probe of anisotropy in atom-molecule collisions via quantum scattering resonances
• Cold heteromolecular dipolar collisions
• New method to study ion-molecule reactions at low temperatures and application to the H${}_2^{+}$ + H${}_2$ $\to$ H${}_3^{+}$ + H reaction
• Energy dependent stereodynamics of the Ne(${}^3$P${}_2$)+Ar reaction
• Multiple packets of neutral molecules revolving for over a mile
• Quantum rainbow scattering at tunable velocities

Cited by in corpus (8)

• Unravelling the stereodynamics of cold HD-H2 collisions
• Quantum state resolved molecular dipolar collisions over four decades of energy
• Molecular Collisions: from Near-cold to Ultra-cold
• Multistage Zeeman deceleration of atomic and molecular oxygen
• Electric-field-controlled cold dipolar collisions between trapped CH${}_3$F molecules
• Crossover from the Ultracold to the Quasiclassical Regime in State-Selected Photodissociation
• Collisions Between Ultracold Atoms and Cold Molecules in a Dual Electrostatic-Magnetic Trap
• Single-Source, Collinear Merged-Beam Experiment for the Study of Reactive Neutral-Neutral Collisions