Construction of the Lundium chamber

Transformation: TASISpec to Lundium

In the Lund Nuclear Structure Group, which I am part of, one of the main objectives is to perform spectroscopic studies on Superheavy Nuclei.  Up till now, this has been achieved with our decay station TASISpec. However, TASISpec is now being upgraded to Lundium.

In the animation above, the transformation from TASISpec to Lundium is visualised. In the beginning of the animation, the full experimental hall TASCA is shown. At the very right, an accelerated ion beam impinges on a target wheel and once a day or so, the beam and target nucleei fuse together creating a superheavy nucleus. Following this, the synthesised superheavy nucleus is transmitted through one dipole and two quadrupole magnets (red) to the detection set-up on the very left of the image. In TASISpec and Lundium the superheavy nucleus is implanted in a Si-detector (mounted on green PCBs). In the silicon detectors (in total 5),  α-particles following the radioactive decays of the superheavy nuclei are detected. Simultaneously, photons stemming from γ-ray deexcitations or X rays from highly converted transitions are detected in surrounding germanium detectors.

To obtain the highest detection efficiency, the germanium detectors need to be placed as close as possible to the silicon detectors while at the same time covering as much of the solid angle as feasible. In TASISpec the composite germanium detectors have been accessible through European collaborations and were consequently not tailored for the application. In the Lundium upgrade, these germanium detectors will be replaced (as visualised in the animaiton) with a new type of detectors, denoted Compex. These are cubic shaped and offer the possibility for an incredibly compact and efficient decay station through operation in the same vacuum as the Si-detectors. As finally showed in the animation, the new Lundium vacuum chamber is to host all the silicon and germanium detectors.

We are currently working on a characterisation of the new Compex detectors, as described here: 3d-characterisation of HPGe-detectors. In parallel, the Lundium chamber is constructed.

More information is coming.