MAGNETIC MATERIALS FOR PARTICLE ACCELERATION

1. MAGNETIC MATERIALS FOR PARTICLE ACCELERATION R. Hasegawa Metglas, Inc., Conway, SC, USA K. Ogura and T. Yoshida Hitachi Metals, Ltd., Tottori, Japan RPIA 2006, Tsukuba, Japan 07-10 March 2006

2. OVERVIEW • Introduction • Amorphous Alloy Inductors • Nanocrystalline Alloy Inductors • Production of Large Size Cores • Conclusion

3. INTRODUCTION • Materials Considered (past & present): • Ferrites • Fe-based Nanocrystalline Alloys • Fe-, Fe-Ni- and Co-based Amorphous Alloys • Main Features: • Low Q • High Operating Flux Densities • High Accelerating Gradient Operations • Suppression of Coupled Bunch Instability Wider Availability of Core Materials for Specific Cavity Requirements

4. HISTORICAL FT3M FT3L Fe-AM FeNi-AM Y. Tanabe, M. Fujieda, Y. Mori, H. Nakayama, C. Ohmori, K.Saito, Y. Sato, T. Uesugi, M. Yamamoto, T. Yan, E. Ezura, T. Takagi and M. Yoshii, KEK Preprint 98-77 (June 1998)

5. Co-based Amorphous Alloy

6. µQf Product Comparison FT3L and Fe-AM : data of Tanabe et al.

7. Nanocrystalline Alloy

8. Nanocrystalline Alloy

9. Nanocrystalline Alloy (FT3L-13µm) Q

10. Previous Winding Tension Pattern A Pattern B Diameter of Wound Core LARGE CORE PRODUCTION

11. µQf Variability - Core Winding Tension

12. CONCLUSION • Both amorphous and nanocrystalline alloys were • heat-treated with a magnetic field applied along • cores’ axis direction. • µQf > 7 GHz at 1 MHz achieved in amorphous Co- • based alloy and Fe-based nanocrystalline alloy • Q ~ 4 (Co-based amorphous alloy) • Q ~ 1 (Fe-based nanocrystalline alloy) • µ ~ 2000 (Co-based amorphous alloy) • µ ~ 5000 (Fe-based amorphous alloy) • Controlled core winding tension is necessary to • reduce performance variability across cores’ build. • PROVIDE WIDER AVAILABILITY OF INDUCTOR CORE • MATERIAL FOR PARTICLE ACCELERATION