1. NBI 14-19 March 2002 The MiniBooNE Horn Ioanis Kourbanis For The MiniBooNE Collaboration

2. NBI 14-19 March 2002 Outline o List of people o Horn characteristics o Horn Power Supply o Horn Striplines o Highlights of Horn Construction and Assembly o Horn Testing o Horn Changeover o Future Plans

3. NBI 14-19 March 2002 List of People C. Anderson L. Bartotzek (Bartoszek Engineering) L. Bartelson L. Bugel C. Jensen H. Le B. Markel (Markel & Associates) J. Misek F. Nezrick H. Pfeffer R. Reilly D. Snee M. Sorel E. Zimmerman

4. NBI 14-19 March 2002 Horn Characteristics o We are using one horn with a narrow neck and a conical inner conductor (BNL Design) designed to run at a current of 170 KA. o The horn is made out of Al alloy 6061-T6 and is excited by a 143  sec current pulse. o Keep the voltage at the PS below 10 KV (use solid state SCR’s instead of thyristors) o Reduce the current pulse width as much as possible to avoid excessive heating of the horn. o Keep the voltage at the horn as low as possible (small inductance). o The horn will operate at an average rep rate of 5 Hz. Total average power deposited in the horn is 2.4 KW.

5. NBI 14-19 March 2002 3-D Model of the Horn

6. NBI 14-19 March 2002 Horn Power Supply p The Power Supply consists of a Capacitor bank (1,344  F) discharged through an inductive load by an SCR switch. The system has a separate circuit for energy recovery. p The circuit is divided into 16 parallel capacitors, each with its own SCR switch.

7. NBI 14-19 March 2002 Horn PS Parameters

8. NBI 14-19 March 2002 Power Supply Schematic

9. NBI 14-19 March 2002 Power Supply View (Front)

10. NBI 14-19 March 2002 Power Supply View (Back)

11. NBI 14-19 March 2002 Horn Stripline o Balanced design (odd number of conductors) to minimize forces. o The conductor spacing is 1 inch. Fluted alumina insulators with a 2 inch creepage length were used to separate the conductors. o The test stripline piece, along with a clamped joint, were corona tested. o The inductance of the final stripline was measured to be 18.5 nH/m.

12. NBI 14-19 March 2002 View of the Long Stripline Section

13. NBI 14-19 March 2002 View of a Stripline Joint

14. NBI 14-19 March 2002 View of the Small Stripline Section

15. NBI 14-19 March 2002 Construction and Assembly Highlights p Forged Outer Conductor p The water sprayers were vibration isolated from the Horn Outer Conductor. p Solid connections from the striplines to the Horn. p The Horn Inner Conductor was welded at Fermilab using a programmable TIG welding machine.

16. NBI 14-19 March 2002 Outer Conductor after Forging

17. NBI 14-19 March 2002 Outer Conductor after Machining

18. NBI 14-19 March 2002 Outer Conductor after Welding

19. NBI 14-19 March 2002 Water Manifolds

20. NBI 14-19 March 2002 Water Truss

21. NBI 14-19 March 2002 Water Truss and Water Manifolds

22. NBI 14-19 March 2002 Water Truss Bellows Detail

23. NBI 14-19 March 2002 Water Connection Detail

24. NBI 14-19 March 2002 Outer Conductor with Water Truss

25. NBI 14-19 March 2002 Water Drain Connection

26. NBI 14-19 March 2002 Water Nozzle Detail

27. NBI 14-19 March 2002 Twist Transitions

28. NBI 14-19 March 2002 Inner Conductor Before Welding

29. NBI 14-19 March 2002 Hand Scraping before Welding

30. NBI 14-19 March 2002 Welding Sample

31. NBI 14-19 March 2002 Large Weld

32. NBI 14-19 March 2002 Small Diameter Weld

33. NBI 14-19 March 2002 Inspecting the Small Diameter Weld

34. NBI 14-19 March 2002 Radiography of Weld

35. NBI 14-19 March 2002 Radiography of Large Weld

36. NBI 14-19 March 2002 Moving the Inner Conductor from The Welding Machine

37. NBI 14-19 March 2002 Inserting the Inner into the Outer Conductor

38. NBI 14-19 March 2002 Horn Testing p The horn was pulsed for the first time on 07/27/01. p The horn test was completed on 02/12/02 after completing 11M pulses at full current. p We completed horn magnetic field measurements. p Completed a series of vibration measurements. p Things we were monitoring: p Total current p Current in the four striplines feeding the horn p Total voltage p Cooling water supply and return temperatures p Horn temperatures

39. NBI 14-19 March 2002 Overview of MI-8 Test Area

40. NBI 14-19 March 2002 Horn module overview

41. NBI 14-19 March 2002 Stripline Configuration at the TSB

42. NBI 14-19 March 2002 Current and Voltage Profiles

43. NBI 14-19 March 2002 Horn Magnetic Field Measurement

44. NBI 14-19 March 2002 Horn Temperature Profiles with Different Sprayer Configurations

45. NBI 14-19 March 2002 Correlation between Horn and Water Return Temperatures

46. NBI 14-19 March 2002 Horn Vibration Spectrum

47. NBI 14-19 March 2002 Horn Axial Displacement vs. Time

48. NBI 14-19 March 2002 Horn Changeover p The horn module is expected to be highly radioactive (30 Rad/hr at 2 ft). p In order to reduce the Radiation Exposure to under 100 mR/hr at 1 ft, the shielding requirement is 5” of steel on all sides. p Because of the crane lifting capacity, two separate coffins (an inner and an outer ) will be used. p The inner coffin has 1.5’’ thick walls except from the top cover and the front door (5” thick). p The outer coffin has 3.5” thick walls and is open at the top and the front.

49. NBI 14-19 March 2002 Horn Changeover (2) p The radioactive horn module will be stored inside the two coffins in the Target Service Building in the old Proton Line. p Four coffins (two inner and two outer coffins) will be needed for a changeover. p A detailed procedure outlining all the steps for a changeover has been written and reviewed. p Total estimated time for a changeover is 2 weeks.

50. NBI 14-19 March 2002 Inner Coffin

51. NBI 14-19 March 2002 Outer Coffin

52. NBI 14-19 March 2002 Initial Configuration

53. NBI 14-19 March 2002 Inner and Outer Coffins

54. NBI 14-19 March 2002 Open Inner Coffin Door

55. NBI 14-19 March 2002 Position the Coffins next to the Horn Module

56. NBI 14-19 March 2002 Pull the Horn Module in the Coffin

57. NBI 14-19 March 2002 Close Inner Coffin Door

58. NBI 14-19 March 2002 Future Plans p We have started disassembling the Power Supply and the Striplines. p The horn modules will be stored in the inner coffin. p Plan to install the horn in the target pile on May 7. p We estimate to be ready for a horn changeover test on May 15. p We should be ready for beam on June 15. p We have started ordering the large pieces for a spare horn.