IPAC'23 - Student Poster Session Guide

IPAC’23 / STUDENT POSTER SESSION GUIDE 8 Student Poster Session SUPM001 Evaluation of the Impact of REBCO Coated Conductors on the Resistive Wall Impedance of the FCC-hh Nikki Tagdulang (ALBA Synchrotron Light Source) . Montserrat Pont, Thomas Günzel (ALBA-CELLS Synchrotron), Juan O’Callaghan Castella (Universitat Politécnica de Catalunya). The beam screen for the Future Circular hadron-hadron Collider (FCC-hh) has a baseline design based on a copper (Cu) coating. Calculations have indicated that the resistive wall impedance will be the major contributor to the beam impedance for the FCC-hh at both injection and col- lision and that Cu might be on the limit to ensure beam stability. To increase the safety mar- gin, it is desirable to reduce the resistive wall impedance. In this contribution, we present an approach to reduce the beam impedance based on the reduction of the surface resistance of the beam screen coating by using High-Temperature Superconductors based on REBaCu3O7-x coated conductors (REBCO-CCs). These HTS-CCs have transition temperatures around 90K, and critical current densities which are high enough even in the presence of strong magnetic field, being therefore good candidates to substitute Cu in the FCC-hh beam screen which will be op- erating at around 50K and under a magnetic field of 16T. Using experimental data generated on the surface impedance of REBCO-CCs, CST simulations have been performed and the beam impedance has been estimated for an elliptical beam screen with the same vertical dimensions as that of a pure Cu beam screen. A position and REBCO-CCs contribution dependence study to determine the optimum beam screen configuration will be shown. Resistive wall impedance studies using an ellipse is a step forward towards determining the performance of the REB- CO-CCs on the FCC-hh beam screen. SUPM002 Helical undulators from magnetized helices and ring sectors Eyal Magori (Ariel University) . Nezah Balal, Vladimir Bratman (Ariel University). A periodic system of spirally arranged magnetized annular sectors creates near the axis a he- lical field, which is close in structure and magnitude to the field in the set of helical magnets. Such a system of relatively few available magnets can be easier to manufacture and assemble than a system containing magnetized helices made from a single piece. In this paper, we the- oretically study the dependence of the helical field on the number of sectors per undulator period. Short prototypes consisting of longitudinally and radially magnetized sectors, as well as a hybrid system assembled from longitudinally magnetized NdFeB sectors and preliminarily non-magnetized steel helices, was experimentally studied. The maximum measured value of the field on the axis of an undulator with a period of 2 cm and a relatively large inner diameter of 8 mm is 0.7 T. Such undulators can provide a large oscillatory electron velocity and seem promising for increasing the efficiency of FELs and IFELs in various frequency ranges.