May 7, 2015
Max IV is a synchrotron light source fascilty at Brunnshög in northeast Lund. Driving north on the highway from Lund north you can see it to the right. It is at the time writing not completely finished, it will be inaugurated in 2016. On May 7, 2015, I attended the Departmen of Physic's annual excursion, which this year went to Max IV.

In Max IV electrons are accelerated in a 300 meter long linear accelerator to 3.7 GeV, which is then stored in a ring with a 528 meter perimeter. 1 eV (electron volts) is the energy an electron acquires when accelerated in a voltage of 1 volt. GeV is GigaelekronVolt, ie one billion electron volts. It is not electron in itself which is used. It is when the electrons are deflected in a magnetic field that light is generated (synchrotron light). If you let the electrons go around in a circle, you can use the same electrons many times. It is not visible light, but light with shorter wavelengths in the ultraviolet and X-rays. One let light hit the material you want to study. one can say that it is a large microscope. With it, one can study the materials and processes in more detail in space and time than before. Maybe wrong to say light, it is photons with different energies and wavelengths. What we usually say is light are photons with wavelengths to which the eye is sensitive.

The morning was devoted to presentations. From the lecture hall at the top of the office building it has views of the resort and surrounding area. The actual ring with experimental halls. In the middle in the ring is what looks like a maze. We were presented the project. Some new thinking when it comes to magnets. Dipole magnets for holding the electrons to remain in the ring, and quadrupole magnets to focus them to the small dimensions required. It requires high accuracy knowledeg on where the electrons are relative to everything else. Just measure it is an engineering art in itself. The electrons are held in a tube of approximately one centimeter in diameter, the tube must have as good a vacuum as possible. One have to have a good system to get out all the air, pumps and special coating which absorbs oxygen inside the tube. Magnets are water cooled. Electromagnetic fields to accelerate the electrons. Magnets (wigglers) to get the electrons to emit synchrotron radiation.

After lunch was the guided tour of the experimental halls, in the ring, linear accelerator and electron gun where the electrons begin their journey. There is no canon but using eg lasers for ripping the electrons from the atoms in a materials. These electrons are accelerated in the linac to be stored in the ring.

Outside, there has been made a chubby landscape. A sort of park with a small pond with a dock, Bosse's bridge. The landscape is not that it should be neat, but carefully calculated to reduce vibrations from the highway nextby.

Northwards the second major research facility in Lund, the European Spallation the Source ESS, is being constructed. It is international, Max IV is national and part of Lund University. There is also the planned a Science Village. Perhaps it is that the Department Physical is moving there. Also Scania's oldest mill, Odarslövs mill. It looks dilapidated, but is planned to be renovated. Also the farm is renovated.

South is La Strada, before school, hostel, now decaying and hangout with graffiti. Municipality bought it some year ago. The oldest house is removed, perhaps the rest will be demolished too. So believed the guide. If I had to decide, it would have been renovated and the best graffiti retained.

On the other side of the highway is Klosterängshöjden, the height with their Spanish bulls. From there you have a view of Max IV, neighborhood and Lund.

Max IV
European Spallation Sourse (ESS)
Fysiska Institutionen
Lunds Universitet
La Strada
Klosterängshöjden

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