NUMI Flexible Joint/Floating Clamp WBS Power Supply System Level 3 Manager Nancy Grossman FNAL July 10, 2001

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 2 Outline Charge to group Transmission Line/Horn Overview Specifications for Movement of Horn Brief Description of the Present Two Options  Flexible Joint (much more robust design at this stage)  Floating Clamp (very conceptual design at this stage) Rough Comparison of Two Designs

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 3 Charge to Group Ideas to incorporate into either design? Things we have overlooked? Worth spending some engineering time on floating clamp option? Totally different approach that is simple, cheap and reliable?!

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 4 Transmission Line/Horn Overview Transmission Line: Material: Aluminum 6101-T61 Dimensions: 12 inches wide by 3/8 inch thick Width: Stripline nominal width is 12 inches, can reduce to 8” from clamp to horn. Gap: Stripline nominal spacing between bars is 3/8 inch, can increase in flex region.

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 5 Transmission Line/Horn Overview Horn 1: Material: Aluminum 6101-T61. Dimensions: inches wide by 132 inches long and thickness from 2mm to 4.5 mm (inner conductor). Current: 205 KA current pulse every 1.9 seconds, ~1.7 msec long.

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 6 Transmission Line/Horn at MI8 Prototype Horn PS and Transmission line are Installed and Running in MI8  Running 850  sec pulses at 200kA and 1.9 second repetition rate*.  Started running unattended evening and weekends on 3/17/01*.  Pulses to date: ~2e6.  Will have a ~2 msec 204KA and 1.9 seconds repetition rate with the operational PS at MI8.  Similar to the pulse we will have in the Target Hall.

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 7 Specifications for Horn Movement etc. 1. Motion (assume beam is align, perform target scans, moving horns, to cross check survey)  Amount:  1 centimeter vertically and horizontally at each of the two supports.  Motion at the end of the horn where the stripline connects is significantly larger than  1 centimeter.  Surface to which the stripline connects also rotates about the vertical and horizontal axis due to this motion.  Horn 1 expected movement: ~5mm –2 mm rotation –3 mm translation  Horn 2 expected movement: ~8mm –2 mm rotation –63 mm translation  Frequency: 1-2 scans at commissioning, 5 movements per scan, center and one to each side, top and bottom  Resultant force on horn: less than 300 lb.

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 8 Specifications for Horn Movement etc. 2. Cooling  Target chase cooled by ~50,000 cfm flowing in the beam direction in the horn region  Beam heating: ~183 KW/m 3  Electrical heating: ~27 KW/m 3  Assume air cooling from target chase is sufficient (will need to check) 3. Radiation Environment such that ceramics must be used 4. Lifetime:  Part of stripline connected to horn will be replaced each time a horn is replaced, ~ once per year.  Part of stripline within stripline block (includes clamp) does not have to be replaced every time a horn is replaced, but we will most likely have a spare just in case.  Lifetime of NuMI ~ 10 years 5. Vibration: not near horn natural frequencies (200 Hz…)  Biggest horn vibration is from stripline (MI8 measurements)

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 9 Flexible Joint Option Slices in corners and rocking clamps that allow stripline sections to slides relative to one another ZrO 2 for insulating spacers

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 10

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 11 Floating Clamp Option Vertical movement by release clamp and tighten  Access Target Hall, remove concrete, release clamp, move horn, tighten. Horizontal movement by release snubbers in stripline block and tighten.  For horizontal movement, access, release snubbers, move horn, tighten.  Need to release clamp too for horizontal movement?

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 12 Rough Comparisons

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 13 Rough Comparisons

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 14 Costs - Not well Known No flex joint and no floating clamp (no movement):  Four Solid joints:  Three Clamps (two plus prototype?):  Total: Flex Joint:  Five Flex joints:  Three Clamps:  Total: Floating clamp:  Four (?) Solid joints:  Three Floating Clamps:  Total:

NUMI Internal NuMI Review July 10, 2001 Flex Joint/Floating Clamp Page 15 Charge to Group Ideas to incorporate into either design? Things we have overlooked? Worth spending some engineering time on floating clamp option? Totally different approach that is simple, cheap and reliable?! Ingrid will present status of flexible joint (30 minutes) Kris will discuss the floating clamp design (15 minutes) Discussion -> Comments to us within a week, help us to decide how best to proceed