The MAX-Wiggler: Design, Construction And Commissioning Of A 3.5 T Superconducting Wiggler With 47 Poles

The increasing demand for high fluxes of x‐rays to perform crystallography and material physics at MAX‐lab is met with the MAX wiggler. The MAX‐Wiggler is a cold bore superconducting wiggler with 47 3.5 T poles and a period length of 61 mm and it has been constructed in‐house at MAX‐lab. The MAX‐Wiggler has now been installed and commissioned on the 1.5 GeV MAX‐II storage ring at MAX‐lab. This paper describes the design and performance of the MAX‐Wiggler and also the studies of the effects of the MAX‐Wiggler on the stored electron beam. The MAX‐Wiggler cryostat is a pool type cryostat with a bath of liquid He where the boiled of He gas is used for cooling different parts of the cryostat. The consumption of liquid He is about 2.5 litres per hour at nominal working conditions with 200 mA of stored current in the MAX II storage ring. The effects of the wiggler on the stored electron beam, of which the vertical focusing effect is the most dominating, have been neutralized by modifying the magnetic optics of the storage ring and the MAX‐Wiggler is now in routine operation at MAX‐Lab.