# Presentation: 804899

## What are the issues with a different Module layout for ILC Dev Module?Or do we want to keep building TTF3+

- Tighter spacing of cavities
- Quad in the center
- Longer QBPM
- get dipole out of quad
- Make sure quad doesn’t saturate
- What kind of BPM
- Some of this discussed a lot in 2000 for TDR
- Carlo notes

## Why am I pushing this?

- I would hate to see modules built at FNAL just be carbon copies of TTFIII+
- Except the “DESY FNAL” module
- Need to order cavities - what beam pipe and other changes should be considered
- Takes so long to get something build, should try evolutionary changes- But don’t bit off too much
- DESY will have its hands full and must move on a different time scale than ILC
- But if things workout on dev modules maybe they could be useful for XFEL as well

## Cavity now 1283mmTDR 1256 mm

## Interconnect now 344mm TDR 283 (110 63 110)

## TDR TESLA Quad/steerer-BPM

- What is necessary for beam based alignment, position stability, vibration, resolution?

## Module Notes from Carlo (~2000)

| In 2000 | 1036.2 + | Cavity | bellows | Ends+bel | Slot L |
| --- | --- | --- | --- | --- | --- |
| *Relaxed-compressed | 110 +110 | 1256 | 63 | 283* | 1319 |
| compressed | 100+94 | 1230 | 70 | 264 | 1300 |
| Orig compres | 100+100 | 1236 | 63 | 263 | 1299 |
| Ref  in 2000 | 102+138 | 1276 | 102 | 342 | 1378 |
| Now |  |  |  |  |  |
| I believe-present Ref | 105.6+141.6 | 1283.4+-3 | 97 | 344 | 1380 infn |
| Tentative sugestion 1st | 105.6+114.4 | 1256 | 89 | 309 | 1345 |
| 2nd Suggest  | 105.6+105.6 | 1247.2 | 77 | 290 (288.2) | 1324+2 =1326 |
|  |  |  |  |  |  |

- * agreed TDR solution

## Cavity interconnect

- Cavity beam tube ends
- Will 105.6 work on both ends? If it works on coupler end now?
- Why 110?, Why 114 (except just to get 1256 as in TDR
- Saclay II tuner will need to be looked at to see if it can be modified- it pusses on the cavity flange
- Bellows
- Need certain length studs to make up the flanges
- That sets the length of the bellows
- Is it reasonable to consider slotted flanges?
- Probably not for rotateable side
- Non rotateable ? Needs mech analysis and test

## Bellows

## Bellows can we make shorter?

- Slot and maybe reinforcing ring?

- Now
- possible

- Slot?

## Module length choices?

- Options
- Make just as long as required for TESLA QBPM design length
- Make as long as present module 12200
- Make the QBPM slot length same as a cavity
- Arbitrarily have chosen 12200 for this analysis

## Module lengths & QBPM

- 1st 1256+89, 2nd 1247+77+2

## Option 2 measurements from center post

## 2nd option module layout

- Symetric posts but are they not out far enough?
- Difficulity at module interconnect??
- What are the interconnect constraints and possibilities?

## QBPM TESLA and option 2

## Conclusions

- Check flange slitting- needs person to seriously work on mechanical design
- Check inter connect space- just how much is really necessary for welding and assembly?
- Check Saclay 2 tuner and if can be modified to fit with shorter end tube
- Need more work to understand the present quad and if it will meet requirements, especially related to residual field and alignment with beam.
- Axel interesting idea of reversing cavities in one half to get couplers away from end
- But it would require 2 cavity types
- Wouldn’t work without other changes in No Q modules

## Length of QBPM & Module options 1 & 2

## Slide 21