# Presentation: 453745

## Proposal for New Configuration of supporting SC Cavities on HGR pipe

**Prashant Khare**
**R.K.Khare**
**Vikas Jain**

## Concept HGR Pipe:  Design for Manufacturing 

**At present HGR pipe supports all cavities in a cryomodule. **
**HGR pipe is manufactured with great precision as cavity alignment depends on it.**
**Required straightness 3 mm in 12 m.length**
**Hence expensive**
**Approach**
**A new design of cavity hanger to accept commercially available pipe.**

**Existing Scheme**

**Alternate being worked**

## Objective for this new proposal

- While  at FNAL I had proposed to  explore the possibility of redesigning alignment block.
- But this idea of splitting Y shaped hanger is something new.(Maybe too far fetched.)The Objective is
- To be able to use available Extruded seamless SS pipes.Saves money and time both.
- Save money by eliminating the machining operation of entire welded structure (pipe plus the Y shaped hanger of cavities).

## Proposal for a different Supporting scheme

- It is proposed to split the “Y” shaped hanger in two parts.
- The top part can be laser welded to the pipe.
- The bottom part will be put on surface plates which are coplanar.
- The bottom parts of hangers will be aligned . and clamped on it.

## HANGER,CAVITY & LUG

## Split hanger

## Proposal (contd.)

- In the next step the pipe along with upper part of Y shaped hanger will be placed above the aligned supports.
- The T and C shaped supports will be placed at whatever position they get placed, by virtue of the irregularities in the pipe’s shape.
- These T and C shaped parts will be welded with a laser in pulse mode so that there is no distortion.

## T & C Shaped parts

**With This step irregular shape of pipe does not disturb cavity supporting part (i.e. lower part of hanger).**

## Laser welding

**Laser welding with  Nd-Yag in pulse mode ensures that no welding distortion takes place at bottom part of hanger.**

## What we want to Achieve

**So what we may achieve is that the  cavity axis which depends on lower part of hanger is unaffected by irregular shape of pipe.**
**It further prevents machining of a 12meter long structure. Which surely is an arduous task.**

## Problems anticipated

**Some changes in the top support plate.**
**During contraction the pipe may induce a shift of about 100 microns in Y-Y direction,if we assume a camber of 20mm.**
**This could be offset by giving an initial pre defined,calculated offset**.

## Slide 12

## Case 1 -  F. E. analysis (Camber of 20mm in vertical plane)

## Results

## Case 2 -  F. E. analysis (Camber of 20mm in Horizontal Plane)

## Results

## Please let us know what are the problems in this concept.

## Update on End Group Machining from single block  

**The first Prototype made in copper was presented in the last meeting**

## Update on End Group (contd.)

**The second Prototype made in copper is also ready. **
**This is made to dimension with all tolerances.**
**Inspection pending.**
**Contrary to the quantity projection last time ,it is requested that at least four solid cylindrical blocks of Dia.155mm and length 125mm will be needed.**

**Next Step**
**We are now at a stage where we will need Niobium material very soon.**

## 

THANKS

- THANKS