March8-11RRCAT < SPL

SPL Web>Linac4Web>CollaborationMeetings>IndiaRRCAT>March8-11RRCAT (2011-05-20, FrankGerigk)

Jacks and wave-guide couplers for Linac4, meeting 8/9 March 2011 at RRCAT, Indore, India

1. Introductory presentation by F. Gerigk
2. Jacks
3. Wave-guide coupler

1. Introduction

The possibility of producing the Linac4 jacks and wave-guide couplers was discussed and the construction details were discussed on the specification drawings. It is likely that the jacks can be produced at the "Indo-German Tool Room", a company which has already produced all of the LHC jacks. The wave-guide couplers would be produced directly at RRCAT, with the support of local sub-contractors. P.D. Gupta, the director of RRCAT was very supportive and is ready to give a certain priority to this project.

2. Jacks

A discussion was held with C.S. Sharma, the director of the "Indo-German Tool Room", a local company in Indore, which would produce the jacks.

Questions and answers and actions:

action	institute/person	status/result	completed
clarify which pieces are commercially procured	CERN, F. Gerigk	done see Figure 1,2	2011-03-22
Can AL 6060 be replaced with 6063	CERN, F. Gerigk	done yes	2011-03-22
Propose a replacement for AL 6082	IGTR, C.S. Sharma	done 6082 can be procured in India	2011-03-25
Piece No.4: can surface hardened (with electroless Nickel plating) EN19 be used, as it was done for the LHC jacks?	CERN, F. Gerigk	confirmed
Prepare delivery of commercial pieces for a pre-series of 3	CERN	done ready for shipping	2011-03-22
Replace any plastic pieces with viton	CERN	pending

*Figure 1:* commercial pieces of the jacks: alignment mechanism + bearings

*Figure 2:* pieces of the jacks: commercial pieces are encircled

3. Wave-guide Coupler

During the visit a prototype wave-guide coupler was shown, which was constructed according to the previous design of the Linac4 couplers. The overall impression was very good, but the piece still needs to be cleaned and vacuum tested.

The revised design was discussed and the following questions need to be clarified:

action	institute/person	status/result	completed
send drawings of the electrode used for copper plating at CERN	CERN	done SPLACDTW0010.pdf, Cuivrage_T_guide_donde.pdf, L4-COOPERINGT.pdf, Tooling, picture 1, picture 4
describe machining procedure for flange surfaces, which carry Helicoflex joints	CERN	done the surfaces are first fine machined and then finished by hand with scotch brite in the direction of the joints	2011-03-22
Can TIG welding be used instead of EBW for the race-track shaped welding of the coupling iris?	CERN	yes, but the surfaces of the flanges need to be fine-machined after the weldings. The process needs to be verified on a prototype.	2011-03-22
Can 316 L be used for the flanges instead of 316 LN?	CERN	done no, 316 LN is mandatory, CERN will send the flange material	2011-03-22
Should we consider to make 2 prototypes: i) according to drawings with bent sheets, ii) one with 4 welds	CERN	done version i) should be retained because this makes it easier to have vacuum tight welds and it minimises the risk of trapping chemicals (from the Cu plating process) in small volumes.	2011-03-22
Which pieces can be sent by CERN?	CERN	done CERN will send all raw material	2011-03-22
Can the tolerances of the interior length and height be increased from -+ 0.5 mm to -+ 0.7 mm?	CERN	done this might be acceptable for the interior but not for the flanges, the difficulty is how to do the welding of the large wave-guide flange when the tolerances are relaxed on the interior. For the time being we keep these tolerances and see what can be achieved on the prototype.	2011-03-22
Are the long weldings on the bent pieces done from the inside? Can these be done with 5 mm penetration from the inside + a closing weld (1 mm) from the outside?	CERN	done at CERN these welds were done as plasma welds with full penetration from the outside. Closing welds should not be used because they still carry a risk to develop small volumes which may trap chemicals from the Cu plating process.	2011-03-22
Can RRCAT use plasma welding?	RRCAT	done RRCAT is considering to procure the equipment	2011-03-25
Is it reasonable to first do all port weldings, then the large L-shaped pieces, and then the fine machining of the flanges?	CERN	done yes, this is the preferred procedure	2011-03-23
Are the welds on the circular flanges done with or without filler?	CERN	done welds were done at CERN without filler	2011-03-23
Provide documents for cleaning procedures, which are mentioned in the drawings	CERN	done
Are the thin welds (3 mm) done from the outside?	CERN	done yes, full penetration from the outside	2011-03-23
Description of welding parameters	CERN	done * For vacuum applications we can only accept full-penetration welds. * For 6 mm thick steel sheets, the only techniques which are suitable are plasma welding (PW) or electron beam welding (EBW). * At CERN these thick welds have been done via EBW, so we cannot give any advice on parameters for plasma welding. * The plasma welding equipment at CERN has evolved over many years and comes from a mixture of suppliers, and it will not be very helpful to you if we give you this list. * The process of plasma welding is apparently very delicate and finding the correct welding parameters is a process that has to be developed for each type of weld. The parameters will also depend on the type of equipment which you have available. At CERN the welders who do plasma welds are regularly sent to training sessions, because apparently it is a very specialised operation that cannot be done by someone who is only familiar with TIG welding. * If RRCAT considers to procure plasma welding equipment, then also a specialist is needed to handle the equipment. * Another option would be if you find a subcontractor who can do either EBW or PW.	2011-03-29

-- FrankGerigk - 22-Mar-2011

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who
pdf	Cuivrage_T_guide_donde.pdf	r1	manage	78.6 K	2011-04-12 - 19:51	FrankGerigk
pdf	Gerigk-CERN-Indore.pdf	r1	manage	876.2 K	2011-03-22 - 10:44	FrankGerigk
jpg	Jacks_01.jpg	r1	manage	229.2 K	2011-03-22 - 10:58	FrankGerigk
pdf	L4-COOPERINGT.pdf	r1	manage	40.4 K	2011-04-12 - 19:51	FrankGerigk
jpg	Outillage_cuivrage-2.jpg	r1	manage	70.6 K	2011-04-12 - 19:52	FrankGerigk
jpg	Picture_001.jpg	r1	manage	398.3 K	2011-04-12 - 19:53	FrankGerigk
jpg	Picture_003a.jpg	r1	manage	449.5 K	2011-04-12 - 19:54	FrankGerigk
jpg	Picture_004b.jpg	r1	manage	445.5 K	2011-04-12 - 19:54	FrankGerigk
pdf	SPLACDTW0010.pdf	r1	manage	151.8 K	2011-04-12 - 19:50	FrankGerigk
jpg	photo.JPG	r1	manage	873.6 K	2011-03-22 - 10:52	FrankGerigk

Topic revision: r5 - 2011-05-20 - FrankGerigk

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