CERN, February 2014

CERN, February 2014

CERN-MAX IV collaboration on vacuum design

Pedro Costa Pinto on behalf of the CERN-MAXIV team:

S. Calatroni, P. Chiggiato, L. Ferreira, M. Mensi, D. Letant-Delrieux, S. dos Santos, M. Taborelli, CERN-TE-VSC

E. Al Dmour, Marek Grabski, Pedro Tavares, MaxLab.

Vacuum, Surfaces & Coatings GroupTechnology Department

Pedro Costa Pinto, CLIC workshop 2014, CERN.

1 Brief introduction to MAX IV

2 The vacuum system

3 CERN contribution (phases 1,2 and 3)

4 Summary

OUTLOOK


1 Brief introduction to MAX IV“The MAX IV source will be the most brilliant synchrotron light source in the World and will by far exceed the performance of other third generation synchrotron radiation facilities.”

https://www.maxlab.lu.se/node/1055

2015

“MAX IV sources will, in particular, facilitate imaging and microscopy methods with unprecedented spatial resolution and simultaneous sensitivity to chemical, electronic, geometric, magnetic, etc. structure.”


2013



1 Brief introduction to MAX IV“The MAX IV source will be the most brilliant synchrotron light source in the World and will by far exceed the performance of other third generation synchrotron radiation facilities.”


2015

“MAX IV sources will, in particular, facilitate imaging and microscopy methods with unprecedented spatial resolution and simultaneous sensitivity to chemical, electronic, geometric, magnetic, etc. structure.”


“…It is also a very energy efficient facility due to the technical design of the accelerator and the buildings.”

“The smaller magnets, the lower frequency used in the RF cavities and the NEG coating in the storage rings makes the MAX IV less energy consuming than any other synchrotron.”

“The total power consumption of magnets in the 3 GeV MAX IV is about half of that in the MAX II ring even though the MAX IV facility is five times bigger.”



1 Brief introduction to MAX IV


Circumference (m) 528

Nr of straight sections 20

Injection full energy, top-up

Stored current (mA) 500

Horizontal emittance (nm rad) 0.2 - 0.3

Vertical emittance (nm rad) < 0.008

Horizontal beam size (σ µm) 42- - 52

Vertical beam size (σ µm) < 6

3 GeV ring20 SECTORS (ACHROMATS)

1 23

456

789101112

1314

151617

1819 20



2 The vacuum system

CERN – MAX IV collaboration on the design/construction of vacuum chambers


Limited space for vacuum pumps

NEG coating

Cu chambers NEG coated

Bellows welded to the chamber => difficult to clean

Narrow gap antechambers hard to coat


2 The vacuum system



2 The vacuum system



2 The vacuum system

Standard vacuum chambers

Distributed cooling

Ribs

Cooling for corrector

area

Cooling for corrector area

Welded bellows

Welded bellows

Chamber body

Inside diameter: 22 mm, Total length: 2.5 m,

Bent part: Arc length 1 m, Bending angle 30, Bending radius 19 m.

Beam direction

Bent part

U1, VC3

Beam direction



2 The vacuum system

complex vacuum chambers

Beam direction


VC1

VC2A

VC2BVC2L


2 The vacuum system

complex vacuum chambers


Vacuum chamber for emittance measurement


3 phases:

3 CERN contribution

ID 22 mm


Phase 1: Define global strategy and prepare the route for the production of standard chambers by licensed companies/institutes.

Phase 2: R&D to set coating procedure/technology for the complex chambers and compatibility with manufacturing techniques.

Phase 3: Coat at CERN the complex chambers.


1- Define the type of Cu for the beam pipes: OFS (resistance to thermal cycling, as for the Long Straight Sections of the LHC)

3 CERN contribution: phase 1

2- Define surface treatment procedures to ensure compatibility between the assembling techniques and the NEG coating.

3- Degreasing, etching and quality control of the 300 copper tubes before start mechanical assembling.

ID 22 mm



1- Define the type of Cu for the beam pipes: OFS (resistance to thermal cycling, as for the Long Straight Sections of the LHC)


2- Define surface treatment procedures to ensure compatibility between the assembling techniques and the NEG coating.

3- Degreasing, etching and quality control of the 300 copper tubes before start mechanical assembling.

4- define coating procedure for standard chambers, coat prototype, measure pumping speed and make know how available to external companies (for series production);

ID 22 mm


Courtesy Marek Grabski, MaxLab.

thickness distribution OKComposition OK

Activation OKPumping speed OK

ID 22 mmcompleted




5- develop coating technology for complex chambers: on going; problems with “delayed activation” in photon antechamber.





thickness distribution OKComposition OK

Activation “delayed” in the photon antechamber => under investigation





6- evaluate compatibility of mechanical assembly techniques with NEG coating: on wire eroded parts and on brazing.

NEG-coatingWire eroded chamber tested: OK (adhesion + activation).





6- evaluate compatibility of mechanical assembly techniques with NEG coating: on wire eroded parts and on brazing.

Copper-Copper brazing:adhesion OK

activation: NOT ACTIVATED(strong carbon contamination and Si; origin not yet

clarified; sample manipulation?)

Copper-Stainless Steel brazing:adhesion OK

activation not tested because the sample was manipulated the same way as the copper-

copper brazing.




7- coating of the complex chambers at CERN (21xVC1 + 21xVC2A + 21xVC2B + 21xVC2L + 1x chamber for emittance measurements). Beginning of the coating production foreseen for March.

VC1 and VC2L will be coated in the systems for the LHC => in concurrence with LS1(priority given to LS1 activities!)




VC2A and VC2B will have a dedicated coating system (under construction)

VC2AVC2B

VC1 and VC2L will be coated in the systems for the LHC => in concurrence with LS1(priority given to LS1 activities!)

7- coating of the complex chambers at CERN (21xVC1 + 21xVC2A + 21xVC2B + 21xVC2L + 1x chamber for emittance measurements). Beginning of the production foreseen for March.




WeeksFEBRUAR

Y6

7 8 9 MARS10 11

VCa-b Pumping system

First test on two plates

XPS analysis Test XPS

analysis

VC2l Test hollow cathode

XPS Activation

First chamber Production

VC1 Drawing of supports(Max IV team) Building supports

12 13 April14 15 16 17

Neg Coating of extension

Construction of the table

Production(XPS ok)

Production

Production

Weeks

May18 19 20 21 22 June

23

VCa-b Production

VC2l Production END

VC1 Production

24 25 26 July27 28 29

Productin END

Production

30 32Augus

t32

33 34 35

Production

WeeksSeptemb

er36

37 38 39 October40 41

VCa-b

VC2l

VC1 Production

42 43Novemb

er44

45 46 47

Production END





8- Assist MAX IV for the activation of the NEG in the ring.



3 Summary


Phase 1 was completed: all tubes treated at CERN and know how for standard chambers transferred.

Phase 2 is reaching the end: coating strategy for complex chambers defined; still under investigation are the delayed activation on photon chamber and the activation of the NEG on the brazing.

Phase 3 is in preparation: production shall start in March for VC2L and April for VC2A, VC2B and VC1. End of production foreseen for the end of the year.

Early the NEG coating is considered in the design phase, smoother and less risky will be the integration of this technology in the fabrication

process.

Thank you for your attention

The overlap of with LS1 activities delayed strongly the R&D and production for MAX IV. (4 months delay)

In spite of the LS1, we took the risk to go ahead with this project because it was an opportunity to acquire know how on coating small aperture beampipes.

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CERN, February 2014

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