1. Design of a demonstration of Magnetic Insulation and study of its application to Ionization Cooling for a Muon Collider Project 38b-911255 John Keane Particle Beam Lasers,INC Team J. Kolonka, R. Palmer, H.Kirk, R. Wegglel, R. Scanlan, D. Clines, R Gupta, A.Garren Special Thanks to Ditktys Stratakis

2. INITIAL THOUGHTS ON “E” FIELD COUPLING TO AN 800 MHZ. CAVITY USING MICROWAVE STUDIO SOFTWARE What an RF Engineer Wants to Talk About

3. Problem There are two significant technical challenges in the development of the required intense muon beams. The first is the production and collection of the muons The second is the reduction of the phase space (cooling) of the muon beam in order to obtain the required beam properties. Such cooling involves the reduction of the beam extent in 6-D phase space

4. Ionization Cooling Fast Enough The magnitude of 3-dimensional momentum vectors of the muon particles are reduced via energy loss in an ionization media, followed by the subsequent restoration of only the longitudinal momentum component with rf power BUT Lattices require that rf used for reacceleration should operate in strong axial magnetic field but rf cavities do not work well in these fields due to multipactoring. This SBIR intends to design an experiment to test the idea of magnetic insulation and to study its application to the required lattices the required lattices

5. Final transverse cooling in high field solenoids It is the design and optimization of Ionization Cooling at the last stage that our study would be devoted to. Anticipated low longitudinal emittance allows us to do the final cooling in a channel without dispersion or wedges; a channel that cools only in the transverse direction allowing the longitudinal emmitance to rise. Final transverse emittance requires stronger focusing than practical with a 6-D cooling lattice. HTS can reach fields of 50 T Rise in longitudinal emittance, resulting from cooling at low momentum, can be tolerated

8. Technical Objectives For the design of a demonstration of magnetic insulation 1. Design a combination of coils and cavity geometries to give magnetic insulation on the rf cavity. 2. Study and compare the technical requirements for pulsed copper and HTS coils. 3.Determine forces between the coils and determine the requirements to restrain them. 4.Design the rf cavity and coupling to an rf waveguide. 5.Make engineering drawings of the experiment. 6.Build and test in liquid nitrogen a copper pulsed solinoid.

9. Technical Objectives: For the design of magnetically insulated cavities for a muon cooling 1.Optimize the magnetically insulated rf reacceleration systems for the use in 6D cooling lattices, to maximize their acceleration gradients relative to the maximum surface gradients which will limit the cavity performance. 2. Design LTS, HTS, or Nb3Sn coils to provide magnetic insulation of the cavities. 3. Simulate the 6-D cooling performances, and optimize that performance by adjusting the dimensions and magnetic field strengths.

10. Initial goals for coupling to 805 Mhz. Cavity We are looking for gradients of 50MV/M From superfish using our most recent design Emax /E0 =4.1164 50/4.1164=12.15MV/m Power= 32.6979 KW for 1MV/m Power needed is (( 12.15)^ )(32.7)= 4.8 MWatts at room temperature This may go down if we use half cell

12. Half Cell Model This is basic model This is for normal conductors The cavity aperature drives into a ¾ wavelength coax lie

13. Variable coax length Variable probe length

14. Use Eigenmode JDM solver Adjust cavity blends for frequency Cavity is made of lossy metal

15. Coax added Use the Q measurements to identify the rightmode

16. Boolien Devil

17. He strikes again but this time worse

18. Flange added. When in Frequency solver eliminated lot of clutter

19. Add Waveguide: Booline Again

20. – Adjustable aperture at boundary.

21. Voltage Max away from aperture

22. Over coupled Voltage min. 337-222=115 (WL=93mm air) 222-115 = 107mm near aperture

23. Conclusions New computer at BNL with more RAM Remote hookup so can work from home Progress on using Microwave Studio Action plan for coupling to cavity Introduction to the “Guys and gals Good memories of time spent with Kurt Owen, Phil Livdahl, and Don Younge