What’s Inside a TESLA Cryomodule Tom Peterson Proton Driver Meeting February 9, 2005

February 9, 2005, Proton Driver Meeting Tom Peterson2 TTF cryomodule

February 9, 2005, Proton Driver Meeting Tom Peterson3 TTF cryomodule

February 9, 2005, Proton Driver Meeting Tom Peterson4 TTF cryomodule

February 9, 2005, Proton Driver Meeting Tom Peterson5 Sources of Information Slides and information from: –Bernd Petersen, Lutz Lilje, Axel Matheisen, Nick Walker, Hans Weise, and others (DESY) –Carlo Pagani (INFN) –Terry Garvey (LAL-Orsay) –Tom Nicol (Fermilab) –Don Mitchell (Fermilab) –John Weisend (SLAC) –TESLA TDR (March 2001)

February 9, 2005, Proton Driver Meeting Tom Peterson6 Recommended! The video of Hasan Padamsee’s presentations here this past December will soon be available from Fermilab’s Visual Media Services as a DVD or streaming video This will include the video of the TTF module assembly process, which Hasan showed us on December 17

February 9, 2005, Proton Driver Meeting Tom Peterson7 Also packed with information... –Links to talks presented by Lutz Lilje, Axel Matheisen, W.- D. Mueller, Bernd Petersen, Nick Walker, and others at our December 6 - 7, 2004, module meeting at DESY –“First ILC workshop,” November , 2004 at KEK –DESY TESLA page with link to the TESLA Design Report and other information including talks and posters from the March 2004 ITRP visit

February 9, 2005, Proton Driver Meeting Tom Peterson8 Look at TTF module CAD models and photos Updated module drawings are promised from DESY, but we do not have them yet TTF module (TTF-III) features vs. TDR –Eight structures per module (12 in TDR) –Quadrupole at the end of the module (TDR placed it at the center) –Invar rods fix modules axially (both TTF-III and TDR) Upgrades for X-FEL (and probably for us) –Place the quad at 2 K –Cold shield can then be K –Quad may move to the center of the module

February 9, 2005, Proton Driver Meeting Tom Peterson9 Cryomodule--helium vessels in the vacuum vessel CAD model by Don Mitchell, Fermilab

February 9, 2005, Proton Driver Meeting Tom Peterson10 Cryomodule--helium vessels in the vacuum vessel with input couplers and the quadrupole CAD model by Don Mitchell, Fermilab

February 9, 2005, Proton Driver Meeting Tom Peterson11 Some TESLA Requirements (from John Weisend, July 2004) ComponentTransverse tolerance Axial tolerance Rotational tolerance Cavity+/- 0.5 mm+/- 5 mm- Quadrupole+/- 0.2 mm+/- 5 mm0.1 mrad Temperature LevelPredicted Static Heat Leak ( W ) 70 K K K2.8

February 9, 2005, Proton Driver Meeting Tom Peterson12 TESLA cryogenic unit

February 9, 2005, Proton Driver Meeting Tom Peterson13

February 9, 2005, Proton Driver Meeting Tom Peterson14 TESLA Cryogenic System Overview Saturated He II cooled 2 K Helium gas thermal K Helium gas thermal K Two-phase line (liquid helium supply and concurrent vapor return) connects to each helium vessel Two-phase line connects to gas return once per module A small diameter warm-up/cool-down line connects the bottoms of the He vessels (primarily for warm-up) Subcooled helium supply line connects to two-phase line via JT valve once per “string” (~10 modules)

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February 9, 2005, Proton Driver Meeting Tom Peterson16 TTF cryomodules #4 through #8

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February 9, 2005, Proton Driver Meeting Tom Peterson22 Active Tuner Actively compensate the detuning of the cavity during the RF pulse by mechanical means to reduce power consumption Piezoelectric elements are suitable for this application (heavily used for fuel injection in car industry) Proof-of-principle done A lot of engineering needed –Choice of tuner –Choice of Actuator –… From Lutz Lilje Dec 04 presentation

February 9, 2005, Proton Driver Meeting Tom Peterson23

February 9, 2005, Proton Driver Meeting Tom Peterson24 Blade tuner concept

February 9, 2005, Proton Driver Meeting Tom Peterson25 Helium vessel string in clean room

February 9, 2005, Proton Driver Meeting Tom Peterson26 Helium vessel string in clean room

February 9, 2005, Proton Driver Meeting Tom Peterson27 Cavity Interconnect

FNAL Module February 9, 2005, Proton Driver Meeting Carlo Pagani 28 Module assembly picture gallery – 3 bis Internal details

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February 9, 2005, Proton Driver Meeting Tom Peterson30

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February 9, 2005, Proton Driver Meeting Tom Peterson33 TTF helium vessel string

February 9, 2005, Proton Driver Meeting Tom Peterson mm gas return pipe as structural support Standard tolerances for high-quality welded pipe (+/- 5 mm), including straightness Lower post flanges, end flanges, and cavity supports are welded to the pipe Pipe weldment is stress relieved The axis defined by end flange centers is transferred to the lower post flanges Cavity support flanges are machined relative to pipe axis Similar procedure for vacuum vessel for post-weld machining of upper post flanges and coupler port flanges

February 9, 2005, Proton Driver Meeting Tom Peterson35 TTF helium vessel string

February 9, 2005, Proton Driver Meeting Tom Peterson36 Helium vessel supports

February 9, 2005, Proton Driver Meeting Tom Peterson37 Runner Pad Rolling needles C-shaped support Spring Washers Four C-shaped stainless steel elements clamp a titanium pad welded to the helium tank. Rolling needles reduce drastically the longitudinal friction Cavities are independent from the elongation and contraction of the HeGRP. Lateral and vertical position are defined by reference screws Longitudinal position can be fixed by the use of an Invar rod Cavity supports principle From Lutz Lilje, Dec 04 presentation

February 9, 2005, Proton Driver Meeting Tom Peterson38 Moving cavity string to cantilever

February 9, 2005, Proton Driver Meeting Tom Peterson39 Support posts

February 9, 2005, Proton Driver Meeting Tom Peterson40 Thermal shield installation

February 9, 2005, Proton Driver Meeting Tom Peterson41 Thermal shield installation

February 9, 2005, Proton Driver Meeting Tom Peterson42 Vacuum shell installation

February 9, 2005, Proton Driver Meeting Tom Peterson43 TTF cryomodule

February 9, 2005, Proton Driver Meeting Tom Peterson44 TTF cryomodule

February 9, 2005, Proton Driver Meeting Tom Peterson45 Module end

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February 9, 2005, Proton Driver Meeting Tom Peterson47 Some History of Changes in Design Features for TTF Cryomodule Three “generations” of TTF cryomodule designs TTF-I was module #1 TTF-II was modules #2 and #3 TTF-III is modules #4 - #8 X-FEL modules will differ in some details from TTF TDR called for some significant changes from all of the above such as a longer module with 12 cavities per module

February 9, 2005, Proton Driver Meeting Tom Peterson48 TTF cryomodules #2 and #3

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February 9, 2005, Proton Driver Meeting Tom Peterson50 3 rd Generation Cryomodule Allows for fixed couplers –Invar rod and roller bearings allow cavities to remain fixed while the 300 mm tube shrinks Eccentric disks are gone –More intuitive alignment results Smaller cross section results in standard pipe size for outer vessel Axial position of last support changed to stiffen structure near quadrupole

February 9, 2005, Proton Driver Meeting Tom Peterson51 Helium vessels Original design was to flow through helium vessel, no separate 2- phase pipe Smaller vessel has advantages but limits heat transfer from the cavity to around 30 W For CW operation or other high heat load operation of a few cavities, one could consider reverting to this type of helium vessel

February 9, 2005, Proton Driver Meeting Tom Peterson52 TDR cryomodule main features Based on 3 rd generation TTF cryomodule design, but ~17 m as opposed to 12 m. 38 inch OD carbon steel vacuum vessel. Two thermal shields, at 5-8 K and K. MLI on both shields, the cavity helium vessels, and the gas return pipe. Twelve 9-cell cavities, quadrupole, steering dipole, BPM. Magnetic shielding is integral to the cavity helium vessel. Cryogenic piping is integral to the cryomodule vessel. More elaborate scheme for fixing cavity position axially

February 9, 2005, Proton Driver Meeting Tom Peterson53 TDR 17 meter module fixed pts