In yet another first, the past two weeks at DESIREE have been devoted to our first user beamtime focused on merged beams experiments. Gustav Eklund, a PhD student from Stockholm University, has been examining mutual neutralization reactions between H- and cold HD+ ions.

Who are you; where are you from?
I am a PhD student at the atomic physics group at Stockholm University. So I'm quite familiar with the facility.

What is your research in general?
As a local member of the atomic physics group I have some part in most experiments at DESIREE. My work has been mainly focused on rotational relaxation of small molecular ions that are stored in the cold environment of DESIREE. Recently I have been more involved with merged beam experiments.

How will your experiments at DESIREE further your research?
This week we are looking at mutual neutralisation of D- and HD+. We are primarily interested in investigating whether the resulting neutral HD dissociates or not, and how this potential dissociation process is dependent on the collision energy of the two beams.

Are there any unique capabilities of DESIREE that you are exploiting?
Quite a few actually! In this experiment we want to utilize DESIREE to perform merged beam experiments with positive and negative ion beams. This is one of the first merged beam experiments we are attempting so it's exciting to see how it will work out. The nice thing about performing these experiments in the cold environment of DESIREE is that the molecular ions are vibrationally and rotationally cooled as they are stored in the ring. This limits the number of available reaction channels and simplifies the results.

How do you find it to work at the infrastructure?
There is good support from the staff working here. There is always someone willing to help you with technical matters or discuss the experimental results.