Bahrdt, J.; Bakos, J.; Gaebel, S.; Gottschlich, St.; Grimmer, S.; Kuhn, C.; Knaack, S.; Laube, F.; Meseck, A.; Rethfeldt, C.; Rial, E.; Rogosch-Opolka, A.; Scheer, M.; Volz, P.: The status of the in-vacuum-APPLE II IVUE32 at HZB / BESSY II. Journal of Physics: Conference Series 2420 (2023), p. 012018/1-6
10.1088/1742-6596/2420/1/012018
Open Access Version
Abstract:
At BESSY II, two new beamlines for RIXS and for X-Ray-microscopy need a short period variably polarizing undulator. For this purpose, the first in-vacuum APPLE II undulator worldwide is under construction. The parameters are as follows: period length λ0 = 32 mm, # periods = 78, minimum gap = 7mm. The design incorporates a force compensation scheme as proposed by two of the authors at the SRI 2018. All precision parts of the drive chain are located in air. New transverse slides for the transversal slit adjustment have been developed and tested. Optical Micrometers measure the gap and phase positions, similar to the system of the CPMU17 at BESSY II. They provide the signals for motor feedback loops. A new UHV-compatible soldering technique, as developed with industry, relaxes fabrication tolerances of magnets and magnet holders and simplifies the magnet assembly. A 10-period prototype has been setup for lifetime tests of the new magnetic keeper design. The paper summarizes the status of the undulator IVUE32.