NonEvaporable getter technology GSI J Kurdal 07102020 Welcome

Non-Evaporable getter technology @ GSI J. Kurdal 07/10/2020 Welcome The upgrade of the SIS 18 will provide the installation of distributed pumping speed by NEG coated vacuum chambers. To show the feasibility of this task, we plan to equip one sector of SIS 18 with NEG coated dipole and quadrupole chambers in April 2006. GSI signed recently a license agreement with CERN about NEG coating. Now we can start to coat chambers. GSI Accelerator-Facility VBE-UHV 1

Outline 07/10/2020 u Present situation u the synchrotron (SIS 18) u the chambers u Results of simulations u What have we done until now u Outlook GSI Accelerator-Facility VBE-UHV 2

The GSI-Accelerator SIS 18 and the FAIR-Project 07/10/2020 SIS 18 serves as injector for SIS 100. SIS 300/100 SIS 18 GSI Accelerator-Facility VBE-UHV 3

The heavy ion synchrotron SIS 18 07/10/2020 n 12 sectors each: n Circumference 216 m n Maximum Bending Power 18 Tm n n Injection n 18 m long 200 mm thin wall (0. 3 mm) dipole and quadrupole chambers 4 TSP 3 ion sputter pumps Extraction GSI Accelerator-Facility VBE-UHV 4

One sector of SIS 18 07/10/2020 Quadrupole group two Dipoles straight section GSI Accelerator-Facility VBE-UHV 5

Quadrupole. Triplete 07/10/2020 The chambers doesn't exist at present and they must be constructed and builded Dimensions: - length 5000 mm - wall thickness 0. 3 mm GSI Accelerator-Facility VBE-UHV 6

Dipole Magnets and Dipole Chambers 07/10/2020 the length of the chamber is about 3000 mm Problem of SIS 18 dipole chambers: - Bending (length=3 m, angle=15°) - wall thickness 0. 3 mm GSI Accelerator-Facility VBE-UHV 7

Simulation with VAKTRAK 07/10/2020 Advantages of NEG-coated vacuum chambers: • Distributed pumping speed for a lot of the residual gases • Solution to the problem of limited conductance VAKTRAK Code by V. Ziemann: • Lower desorption yields for ions, photons and electrons than stainless steel http: //www 3. tsl. uu. se/~ziemann/vakdyn/ GSI Accelerator-Facility VBE-UHV 8

What have we done, on NEG coating and what are the next steps 07/10/2020 Construct and test recently a system for magnetron sputtering. Diameter of the coil = 350 mm 40 A 1200 mm GSI Accelerator-Facility VBE-UHV Now we can coat at present chambers with a length of 1000 mm and a diameter of 250 mm 9

Outlook 07/10/2020 u For the SIS 18 upgrade, in the frame of the FAIR project, the use of non evaporable getter (NEG) films is foreseen. u We want to increase the pumping speed for CO and H 2 more than one order of magnitude. u Calculations performed by means of the Vaktrak code have proved that the installation of NEG coated dipole and quadrupole chambers will lead to a minimale base pressure. u Additionally, the problem of the conductance limited pumping speed inside the magnet sections will be overcame. GSI Accelerator-Facility VBE-UHV 10