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Jan Conrad

Professor Stockholm University Natural sciences Year of admission: 2012

On the front line for research on dark matter
What dark matter consists of is one of the major unsolved problems of physics. Today, researchers believe that they are on the verge of a breakthrough. Wallenberg Academy Fellow Jan Conrad is on the forefront of this exciting development.

Jan Conrad is one of those people who chose his career, or at least was on the track to his future career, as a child. When he was 10-years-old, he wrote a letter to the German physicist Harald Fritzsch who worked together with Nobel Prize winner Murray Gell-Mann. In the letter, he wrote that he thought Harald Fritzch was working with exciting things and wondered if he could send some references.

“He answered with a hand-written letter, which I had hanging in my childhood bedroom throughout my upbringing. I was a little precocious and a bit of a nerd. Many of the books I read were actually far beyond my understanding, but that was an identity I strived for. I wanted to be somebody who worked with theoretical or experimental particle physics, the hardest things.”
This is how it has continued. Attracted by “the hardest things”, Jan Conrad chose to study physics at the University of Hamburg. In the middle of the 1990s, he came to Uppsala University as an exchange student, where he stayed and earned his PhD studying neutrinos in 2003. This was followed by a few years at the CERN particle physics laboratory in Geneva, Switzerland before he returned to Sweden. Today, he has been active at the Albanova University Center at Stockholm University for several years.
He describes himself as a classical researcher whose entire thinking is occupied by the research he is pursuing. He also says that he is very restless and never satisfied.
“Edward Teller, known as the father of the hydrogen bomb, once said that there are two kinds of researchers, namely “drillers” and “diggers”. Drillers are researchers who stick to one problem and drill ever deeper into it. Diggers jump between different problems, approaches and projects. I am actually more of a digger, but before I leave a project, I have to feel that I have achieved some results.”
WIMPs are the main track
As a Wallenberg Academy Fellow, Jan Conrad is working with dark matter. Today, researchers know that regular matter, in other words matter that emits or reflects electromagnetic radiation, only constitutes 5 percent of the universe. Of the rest, 23 percent is dark matter and 72 percent is dark energy.
"It means a great deal since the Wallenberg grant is very flexible. It provides an incredible freedom to engage resources where they are needed most. Of course, it is also recognition for what I have achieved. In that the Wallenberg Foundation has partially financed the FERMI telescope and the HESS telescope, the Foundation’s participation and financing in this research is also much larger than just what is involved in the Wallenberg Academy Fellow."
It is also known that it is the dark matter and the dark energy that give the universe its structure with stars and other celestial bodies collected in galaxies and galaxy clusters. However, it is not known what the dark matter is made of. It is still one of the great unsolved problems of physics, and as such is naturally an irresistible scientific area for a person like Jan Conrad.
There are many candidates for what the dark matter might be, but today the main track is that it is a kind of particles called Weakly Interactive Massive Particles (WIMP). These particles have a mass that is greater than that of a proton, they move relatively slowly and interact weakly with other particles. Astrophysicists believe that WIMPs have existed since the universe was young, but nobody has yet been able to prove that they exist.
“Now we have a concrete hypothesis, a main track in our search for dark matter, which is also extremely well motivated. Many people also expect that we will soon, within five to ten years, find WIMPs. This is why it is so exciting.”
There are three ways of discovering WIMPs. One way would be to produce and possibly track them in the particle physics laboratory CERN. Another would be to look for indirect traces in the form of gamma radiation and other particles that are created when WIMPs clump together in space, collide with each other and are destroyed. Jan Conrad’s and his colleagues’ main activities involve this method.
“Then, there is also a third way, direct detection, which is something we are in the midst of beginning. This method is based on placing sensitive detectors deep into the ground, usually in old mines, and then waiting for a WIMP to come by and collide with an atom in the detector. Then the recoil from this collision is measured. This way, we can get double evidence for the existence of WIMPs.”
Sweden on the forefront
Another thing that makes Jan Conrad’s research especially exciting is that Sweden has made its way to the absolute forefront of the research on dark matter. One reason for this is of course skilled researchers in creative environments. Another reason is access to data from the FERMI telescope, partially financed by the Wallenberg Foundation, which is mounted on a satellite, and HESS, which is land based in Namibia.
“We have begun to realize that it is fully possible that it may actually be us here in Stockholm who discovers WIMPs. In this case, we are not just a small cog in giant machinery that helps out in a corner to make the discovery, but rather it may actually happen here. This is really enjoyable and an incredible driving force.”
What is the greatest challenge?
“It is improving the sensitivity of the experiments and detectors. In indirect detection, one must be able to see very few photons from WIMP destructions, and to be able to distinguish them from the vastly more numerous photons produced by other sources.”
Text Anders Esselin
Translation Semantix
Photo Magnus Bergström

Jan Conrad is one of those people who chose his career, or at least was on the track to his future career, as a child. When he was 10-years-old, he wrote a letter to the German physicist Harald Fritzsch who worked together with Nobel Prize winner Murray Gell-Mann. In the letter, he wrote that he thought Harald Fritzch was working with exciting things and wondered if he could send some references.

“He answered with a hand-written letter, which I had hanging in my childhood bedroom throughout my upbringing. I was a little precocious and a bit of a nerd. Many of the books I read were actually far beyond my understanding, but that was an identity I strived for. I wanted to be somebody who worked with theoretical or experimental particle physics, the hardest things.”

This is how it has continued. Attracted by “the hardest things”, Jan Conrad chose to study physics at the University of Hamburg. In the middle of the 1990s, he came to Uppsala University as an exchange student, where he stayed and earned his PhD studying neutrinos in 2003. This was followed by a few years at the CERN particle physics laboratory in Geneva, Switzerland before he returned to Sweden. Today, he has been active at the Albanova University Center at Stockholm University for several years.
He describes himself as a classical researcher whose entire thinking is occupied by the research he is pursuing. He also says that he is very restless and never satisfied.

“Edward Teller, known as the father of the hydrogen bomb, once said that there are two kinds of researchers, namely “drillers” and “diggers”. Drillers are researchers who stick to one problem and drill ever deeper into it. Diggers jump between different problems, approaches and projects. I am actually more of a digger, but before I leave a project, I have to feel that I have achieved some results.”

WIMPs are the main track

As a Wallenberg Academy Fellow, Jan Conrad is working with dark matter. Today, researchers know that regular matter, in other words matter that emits or reflects electromagnetic radiation, only constitutes 5 percent of the universe. Of the rest, 23 percent is dark matter and 72 percent is dark energy.

It is also known that it is the dark matter and the dark energy that give the universe its structure with stars and other celestial bodies collected in galaxies and galaxy clusters. However, it is not known what the dark matter is made of. It is still one of the great unsolved problems of physics, and as such is naturally an irresistible scientific area for a person like Jan Conrad.

There are many candidates for what the dark matter might be, but today the main track is that it is a kind of particles called Weakly Interactive Massive Particles (WIMP). These particles have a mass that is greater than that of a proton, they move relatively slowly and interact weakly with other particles. Astrophysicists believe that WIMPs have existed since the universe was young, but nobody has yet been able to prove that they exist.

“Now we have a concrete hypothesis, a main track in our search for dark matter, which is also extremely well motivated. Many people also expect that we will soon, within five to ten years, find WIMPs. This is why it is so exciting.”

There are three ways of discovering WIMPs. One way would be to produce and possibly track them in the particle physics laboratory CERN. Another would be to look for indirect traces in the form of gamma radiation and other particles that are created when WIMPs clump together in space, collide with each other and are destroyed. Jan Conrad’s and his colleagues’ main activities involve this method.

“Then, there is also a third way, direct detection, which is something we are in the midst of beginning. This method is based on placing sensitive detectors deep into the ground, usually in old mines, and then waiting for a WIMP to come by and collide with an atom in the detector. Then the recoil from this collision is measured. This way, we can get double evidence for the existence of WIMPs.”

Sweden on the forefront

Another thing that makes Jan Conrad’s research especially exciting is that Sweden has made its way to the absolute forefront of the research on dark matter. One reason for this is of course skilled researchers in creative environments. Another reason is access to data from the FERMI telescope, partially financed by the Wallenberg Foundation, which is mounted on a satellite, and HESS, which is land based in Namibia.

“We have begun to realize that it is fully possible that it may actually be us here in Stockholm who discovers WIMPs. In this case, we are not just a small cog in giant machinery that helps out in a corner to make the discovery, but rather it may actually happen here. This is really enjoyable and an incredible driving force.”

What is the greatest challenge?

“It is improving the sensitivity of the experiments and detectors. In indirect detection, one must be able to see very few photons from WIMP destructions, and to be able to distinguish them from the vastly more numerous photons produced by other sources.”

 

Dark matter is a hypothetical form of matter that does not emit or reflect electromagnetic radiation. Dark matter constitutes approximately 23 percent of the university’s total energy, which according to the theory of relativity is the same as mass. Today, it is not known what dark matter consists of, which is one of the major unsolved problems in physics.

Annihilation: In physics, annihilation refers to processes where a subatomic particle collides with its anti-particle and is destroyed. The total energy released is directly converted to electromagnetic radiation and in some cases to new subatomic particles.


Text: Anders Esselin
Translation: Semantix
Photo: Magnus Bergström