Related papers: Ultraslow radiative cooling of C$_n^-$ ($n=3-5$)
Photodetachment thermometry on a beam of OH$^-$ in a cryogenic storage ring cooled to below 10 K is carried out using two-dimensional, frequency and time dependent photodetachment spectroscopy over 20 minutes of ion storage. In equilibrium…
We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment; DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (C$_n^-$, $n=1,2,3,4$) in a…
We apply near-threshold laser photodetachment to characterize the rotational quantum level distribution of OH$^-$ ions stored in the cryogenic ion-beam storage ring, DESIREE, at Stockholm University. We find that the stored ions relax to a…
Radiative lifetimes of three elements of the nitrogen group have been experimentally investigated at the Double ElectroStatic Ion Ring Experiment (DESIREE) facility at Stockholm University. The experiments were performed through selective…
We have measured the spontaneous neutral particle emission from copper cluster anions (Cu$_n^-$, $n=3-6$) stored at cryogenic temperatures in one of the electrostatic ion storage rings of the DESIREE (Double ElectroStatic Ion Ring…
The intrinsic lifetime of the upper level in the bound-bound 3d$^9$4s$^2$ $^2$D$_{3/2}$ $\rightarrow$ 3d$^9$4s$^2$ $^2$D$_{5/2}$ radiative transition in Ni$^-$ was measured to be 15.1 $\pm$ 0.4 s. The experiment was performed at cryogenic…
The radiative decay of excited states of the negative ion of rhodium, Rh$^-$, has been investigated experimentally and theoretically. The experiments were conducted at the Double ElectroStatic Ion Ring Experiment (DESIREE) facility at…
We have measured the spontaneous and photo-induced decays of anionic gold clusters, Au$_N^-$, with sizes ranging from $N = 2$ to 13, and 15. After production in a sputter ion source, the size-selected clusters were stored in the cryogenic…
The study of cold and controlled molecular ions is pivotal for fundamental research in modern physics and chemistry. Investigations into cooling molecular anions, in particular, have proven to be of key consequence for the production of…
Deeply inside dense molecular clouds and protostellar disks, the interstellar ices are protected from stellar energetic UV photons. However, X-rays and energetic cosmic rays can penetrate inside these regions triggering chemical reactions,…
The intrinsic radiative lifetimes of the $5d^{10}6s$ $^{2}\text{S}_{1/2}$ and $5d^{9}6s^{2}$ $^{2}\text{D}_{3/2}$ bound excited states in the platinum anion $\text{Pt}^{-}$ have been studied at cryogenic temperatures at the Double…
We present new cooling sequences, color-magnitude diagrams, and color-color diagrams for cool white dwarfs with pure hydrogen atmospheres down to an effective temperature $\te=1500$ K. We include a more detailed treatment of the physics of…
A novel type of particle "cooling", called Ionization Cooling, is applicable to slow (v of the order of 0.1c) ions stored in a small ring. The many traversals through a thin foil enhance the nuclear reaction probability, in a steady…
We propose a scheme for laser cooling of negatively charged molecules. We briefly summarise the requirements for such laser cooling and we identify a number of potential candidates. A detailed computation study with C$\_2^-$, the most…
Spontaneous decays of small, hot silver cluster anions Ag$_{n}$, $n=4-7$ have been studied using one of the rings of the Double ElectroStatic Ion Ring ExpEriment (DESIREE). Observation of these decays over very long time scales is possible…
A sputter ion source with a solid graphite target has been used to produce dianions with a focus on carbon cluster dianions, $\text{C}_{n}^{2-}$, with $n=7-24$. Singly and doubly charged anions from the source were accelerated together to…
An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed and put into operation. With a circumference of 35 m, the ion-beam vacuum…
We present measurements of the cooling length $\ell_E$ for hot electrons in a GaAs-based high mobility two-dimensional electron gas (2DEG). The thermal measurements are performed on a long 60 $\mu$m-wide channel, which is Joule-heated at…
Heavy-ion storage rings have relatively large momentum acceptance which allows for multiple ion species to circulate at the same time. This needs to be considered in radioactive decay measurements of highly charged ions, where atomic charge…
We demonstrate the ability to load, cool and detect singly-charged calcium ions in a surface electrode trap using only visible and infrared lasers for the trapped-ion control. As opposed to the standard methods of cooling using…