Status of Horizontal Test Stand (HTS-2)Status of Horizontal Test Stand (HTS 2) Development Efforts

Pradeep Kush, Prashant Khare, RRCAT, India,

Team Members:Team Members:

S.Gilankar, Rupul Ghosh, R.Chaube, Abhishek Jain, A.Laxminarayanan

2-Nov-11 1

1. Introduction to HTS Design Effortg

2-Nov-11 2

Introduction to the Task

A Horizontal Test Stand (HTS-2) is needed to test dressed SCRF cavities before they are finally placed in the cryomodule.before they are finally placed in the cryomodule.

HTS-1 is working at FNAL (Tests: One 1.3GHz cavity at a time).

HTS-2 has to be designed, It is significantly different from HTS-1 as

1 Two SCRF cavities of 650 MHz at a time (other combinations also)1. Two SCRF cavities of 650 MHz at a time (other combinations also).

2. The 650MHz cavities will operate in CW mode, heat load many times up.

3. Operational problems of HTS-1 should be addressed.

The task has become tough because:A) Apart from document on engineering design of vacuum vessel no other

report / design note etc is available on HTS-1.

11/2/2011 3

p gB) Subsystems like power coupler and feed box have not been finalized.

Status

• 3-D Model completed to visualize component assembly.

• Vacuum vessel design almost complete. Engineering Design noteprepared which takes into account pressure vessel calculations as perASME dASME code.

• First level thermal load calculations are over. Thermal Shield analyzedfor steady state and initial runs of transient.

• Cryogenic Support post designed & Scaled down prototype tested.y g pp p g p yp

• Cryogenic circuit is being designed for cryogenic loads.

• Drawings for fabrication have been started.

CHRONOLOGY

2009 : HTS-2 development efforts initiated at RRCAT.

A. Cross cultural study of horizontal test facilities carried out in 2009-2010 .

Aim: To include best features from all facilities . Get design related info.

B. Initiated design for HTS-2, based on literature survey & available

information and drawings from FNAL on HTS-1 for 1.3 GHz cavity.

C. Discussions started with FNAL team for development of FRS document

- A Functional Requirement specification document was prepared by us and submitted to FNAL in Jan 2010.

2-Nov-11 5

- We have received FNAL’s FRS document in Aug 2010.

CHRONOLOGY

D. Somewhere at the end of Feb 2010, it was decided at FNAL that HTS-

2 facility should be capable of testing beta= 0 6 & 0 9 650 MHz CW2 facility should be capable of testing beta= 0.6 & 0.9 650 MHz CW

cavities also with different testing scenarios.

Thi i li hThis implies that :

- Larger diameter of vacuum vessel for testing larger sized 650 MHz CW

iticavities.

- Increased cryogenic refrigeration to test CW 650 MHz cavities, requiring

hi h d i l d t 2 K d t l d itivery high dynamic load at 2 K, compared to pulsed cavities.

2-Nov-11 6

Importance of HTS in SCRF Tech. Development

HTS will be useful for development of following Subsystems

•Check tuner and cavity tuning stability y g y

•Test fundamental power coupler

•Test HOM couplers p

• Measure Q0 Cavity quality measurements; Qo V/s Eacc (MV/m) with all ancillary equipments

• The attainable fields under different conditions• The attainable fields under different conditions

•An excellent system to study cryogenic engineering issues. & Many other Tests

2 Literature Survey2. Literature Survey

2-Nov-11 8

A. Cross Cultural Study of HTS in other labs.

We were looking information on testing 2 Cavities at a time and CW mode operation and different cavities of different type !Refer :Peculiarities of Existing Horizontal Test Facilities: C th t t RF t t f diff t d i ? Can they test RF structures of different design? Pulsed and/or CW operation mode testing? Testing two cavities at a time?

BESSY

Supported from top or bottom?

B. Comparative Study of HTC’s at Contemporary Labs.

HT Facilities Time Projects Purpose

1. CHECHIA (DESY) 1990 XEFEL & Serving for 20 yrs for TESLA1. CHECHIA (DESY) 1990 XEFEL & FLASH

Serving for 20 yrs for TESLA Technology R & D and FLASH (TTF) Operation

2 CRYOHOLAB 2003 CARE St d 700 MH it f2. CRYOHOLAB (Saclay)

2003 CARE Program

Study 700 MHz cavity for proton or 1.3 GHz for electrons (TESLA type)Cavity structures

3. HOBICAT (BESSY)

2004 BESSY FEL & STARS

Testing two 1.3 GHz 9-cell cavity for CW operation (can(BESSY) & STARS cavity for CW operation (can accommodate 500 MHz structures)

4. HTS (FERMI) 2006 ILC & Project X

Test ILC 3.9 GHz & 1.3 GHz Cavity as well as low Beta cavityy

5. HTC (Cornell) 2007 Cornell ERL

Helped to find many problems

3 Details of Design Effort3. Details of Design Effort

2-Nov-11 11

DESIGN EFFORT

The Design Effort can been divided in following activities

• Development of 3-D Model

D i f V V l• Design of Vacuum Vessel

• Design of Thermal Shield

• Design of Cavity Support System (Cryogenic Support Post and

Frame Bridge and Rolling Cart)

• Finalization of Cryogen supply scheme

Different activities have progressed to different levels. After

analytical calculations. Prototyping has started in some of them

2-Nov-11 12

and will start in others soon.

4 3-D Model of HTS4. 3-D Model of HTS

2-Nov-11 13

3-D MODEL OF HTS FOR SCRF CAVITIES OF 1300 / 650MHZ

3-D MODEL OF HTS WITH TWO CAVITIES, 650 MHz

HTS-2 VACUUM VESSEL

November 2, 2011 15

Cavity when supported on the trolley- Another View

3-D MODEL OF HTS WITH TWO CAVITIES 1 3 GHz3 D MODEL OF HTS WITH TWO CAVITIES, 1.3 GHz

HTS-2 SUPPORT SYSTEM

November 2, 2011 17

END VIEW OF SUPPORT SYSTEM

4K Trace LiLine

80K80K Thermal shield

Deflection pattern in HTS I type of SS structure

3 m long structure for HTS II using HTS I type box and rail section

Material SS 304

Maximum deflection 150 micron

Two Alternate schemes for HTS II structure 

Material SS 304Replacing the box  section of HTS‐ I by an ‘I’ section. SS 304

i d fl i l i hi

Material SS 304

Maximum deflection value in this case is about 32 microns

Replacing the box section of HTS I by a ‘Box section’

Material 6061‐T6

Replacing the box‐ section of HTS‐ I by a  Box section .Al 6061‐T6

i d fl i lMaximum deflection value in this case is about 54.8 microns.

Th d t f AlThe advantage of Al comes from faster cool down

Cool down Estimates 

Cool down status of HTS I type SS 304 box and rail structure at 25000 sec

Far from steady state

Cool down status of 6061‐T6 Aluminum ‘C’ section structure at 25000 sec

30

35

Nearly steady state

Variation of thermal diffusivity with 

10

15

20

25

30

SS 304 BALUMINUM ALLOY 6061-T6 C

l Diff

usiv

ity m

2 /hr temperature

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

0

5

10

Ther

mal

Temperature K

5 Design of Vacuum Vessel of HTS5. Design of Vacuum Vessel of HTS

2-Nov-11 22

3‐D model of HTS‐2 vessel

Feed Can port

21

54

3

5

Main CouplerCavity pumping

Support Post Port

Final 3-D model of Vacuum Vessel with changes Final 3 D model of Vacuum Vessel with changes incorporated after feedback from FNAL

Vacuum Vessel Parameters

Preliminary vacuum vessel of HTS-2

Designed value Remark

Diameter of SS 304 Vessel* 46 inch Considering testing of 650 MHz cavity also

Overall Length of Vessel 137 7 inch Considering testing of two SCRFOverall Length of Vessel 137.7 inch Considering testing of two SCRF cavities

Nominal Thickness of 0.375 inchVessel

Verified with ASME Boiler and Pressure Vessel Code Sec.VIII Div 1,(2004)

Calculations Completed for Vacuum Vessel of HTS-2

Following Calculations Have been completed for Vacuum Vessel of HTS-2HTS-2

• Calculations for the Vacuum Vessel Cylindrical Shell Thickness

- As a external pressure vessel (as per UG-28 of ASME VIII, Div. I, Edition 2004 )

V ifi d i t l l ( UG 27 f ASME VIII - Verified as internal pressure vessel (as per UG-27 of ASME VIII, Div. I )

• The Permissible Out of Roundness of the Vessel Cylindrical Shell• The Permissible Out of Roundness of the Vessel Cylindrical ShellThickness(as per UG80 of ASME VIII Div. I Edition 2004)

• Analysis and Calculations for the Stiffening Rings(as per UG-29, ASME VIII, Div. 1)

• Calculations and Analysis for all the vessel Shell Openings/Ports- (external as well as for internal pressure)

Design Calculations Continued

• The Discussion of Multiple Openings

(as per UG42(a) of ASME, VIII, Div. I )(as per UG42(a) of ASME, VIII, Div. I )

• Calculations and Analysis for the Flanges, Bolts and Welds(as per appendix 2 and appendix Y of ASME VIII Div 1)(as per appendix 2 and appendix Y of ASME VIII, Div. 1)

Front End Flange and the Front Vessel Head Rear End Flange and the Rear Vessel Head Rear End Flange and the Rear Vessel Head Calculations for the Other Flnages of Ports

f d UW ( ) ( ) UW d ( ) Referred UW-13 (e) (2), Fig. UW-13.2, section 2-3 and Fig. 2-4 (4a), Appendix 2 of ASME VIII, Div. 1 for weld analysis and calculations of front and rear end vessel head flanges.

• Calculations for the Vacuum Formed Head Shell Thickness(as per UG-33 (a) (1) (a) and UG-32 (d) of ASME VIII, Div. 1)

Design Calculations (Contd.)

• Discussions on the Saddle Support DesignDiscussions on the Saddle Support DesignReferred “Pressure Vessel Handbook” 7th edition by E. Megyesy

• Initial Relief System Calculations• Initial Relief System Calculations

Referred Vacuum vessel engineering note for SMTA Horizontal test C t t (CGA 1 3 1995)Cryostat (CGA-1.3-1995)

• Two more analysis to be performed as per feedback Two more analysis to be performed as per feedback from FNAL

Some Design Calculations Results

Calculation made for

Parameter

Nominal /Actual Value (inch)

Calculated minimum value

required

Remark

Parameter required (inch)

1. Vacuum vessel

0.25 –External pressurevessel

cylindrical shell thickness

0.375 pressure0.029-Internal pressure

Verified

2 Out of Difference between2. Out of Roundness for Cylindrical shell of Vessel

0.2437Difference between max. dia. and min. dia. at any cross section shall not exceed 1%;of Vessel shall not exceed 1%;

3. Calculation and Analysis for the Front and Available Moment Required moment

of inertia ofthe Front and Rear End Flanges as stiffening rings

of inertia of front/rear ring flanges of vessel,I = 2 2236 in4

of inertia of front/rear ring flanges of vessel,

Ireq = 0.968 in4

No stiffening rings required

g gunder external pressure

Iavailable = 2.2236 in4 req

Some Design Calculations Results (contd.)

Calculation made for Parameter

Nominal /Actual Value

(inch)

Calculated minimum value required (inch)

Remark

( ) q ( )

4 Multipule

No additional reinforcement for multiple openings4. Multipule

Openings/ports Verified by calculations multiple openings are required under current design

fi ticonfiguration5. Calculations and Analysis Verified thickness of flanges

d i d & il bl b ltand Analysis for the Flanges, Bolts and Welds

and required & available bolt area as per Appendix 2 and appendix Y of ASME VIII, Div. 1

Verified

Welds6. Calculation of Vacuum 0 315 in 0.0199 in VerifiedFormed Head Shell Thickness

0.315 in Verified

Working on Mechanized End Closure

6 Design of Thermal Shield of HTS6. Design of Thermal Shield of HTS

2-Nov-11 31

Transient Thermal Analysis

First Point

Second Point

Assumption: The cooling pipe is instantaneously filled with 80 K Helium

Geometric Model Meshed  Model

The cooling pipe is instantaneously filled with 80 K Helium,neglecting any longitudinal temperature gradient in the pipe.

Boundary Conditions: 1 gm/sec Helium flow in 10 mm diameter cooling pipe 1 gm/sec Helium flow in 10 mm diameter cooling pipe H= 280 W/m2.K Constant radiation heat flux from 300 K vacuum vessel =1.5 W/m2 Conduction heat in leak of from each support post = 2 62 Watt Conduction heat in leak of from each support post = 2.62 Watt

Transient Thermal Analysis

Results: It is found that 80 K shield

takes 3 h 15 min to attainsteady statey

The max. temp differenceof ~60K after 30 Min.

At steady state temp At steady state, tempdifference is found to be2-3 K

7 Design of Cavity support system7. Design of Cavity support system

2-Nov-11 34

Cavity Support System

Comprises of Two Major SubsystemsComprises of Two Major SubsystemsA. Cryogenic Support PostB. Frame Bridge and Rolling Cart

Present Task

Functional Requirements from HTS-2

1. Total Structural Load Less about 1000 kg (includes 2 Cavities, Frame bridge, Rolling Cart, Thermal Shield)(more than 2 times of what was with HTS-1)

2 Total thermal load through Support Post should be comparable with2. Total thermal load through Support Post should be comparable with what is there in HTS-1(Dimensions of the present CSP of HTS-1 is maintained so that this value does not change)

3. Design is Necessary to Check for Additional Load CapabilityComplete Understanding of Design Necessary for Modification ifComplete Understanding of Design Necessary for Modification if needed.

4. As a Parallel Activity We Are Thinking of Simplifying the Construction to Make Assembly easy.

November 2, 2011 36

Function of CSP

Cryogenic Support Post performs following main functions

Transfers Weight of Cold Cavity at 2 K to Vacuum Vessel at 300 K while Ensuring Minimum Heat In-Leak

1. Support Load of Cold Mass.

2. Minimize Heat In-leak by using Low th l C d ti it G11 T bthermal Conductivity G11 Tube.

3. Support Load of 80 K Thermal Shield3. Support Load of 80 K Thermal Shield

November 2, 2011 2

Design of Support Post

Fi Max Axial Load Carried by Inner JointFo Max Axial Load Carried by Outer Joint

Pi Contact Pressure at Inner JointPi Contact Pressure at Inner JointPo Contact Pressure at Outer Joint

‘f’ -- Coefficient of Friction between G11 Tube and Disc/Ring

‘E’ Y ’ M d l δ Diametral Interference between Tube and Inner Disc

November 2, 2011 38

‘E’ -- Young’s Modulus ‘μ’ -- Poisson’s Ratio of Materials

δi Diametral Interference between Tube and Inner Discδo Diametral Clearance between Tube and Outer Ring

Spread Sheet for Calculation

November 2, 2011 39

Prototyping to validate the Design

•As of now there is no necessity of developing a full scale prototypeas other details of the system are being developed.

•This prototyping work is being done in order to

- Validate our calculations

- These calculations are necessary if somechange has to be made in the CSP

•As we are thinking of removing 4K shield we wanted to calculateh t i th dditi l h t l k iwhat is the additional heat leak in.

•We can also think about simplifying the assembly process for thisCSP hence this prototyping is being doneCSP hence this prototyping is being done

•OFF COURSE full scale prototyping will also be done.

November 2, 2011 40

Load bearing Capacity of Prototype

ID of Al Disc, d1 = 10mmID of G11Tube, d2 = 57.02mmOD of G11Tube, d3 = 63.02mm

Poisson's Ratio Al 6061T6c Disc μ1 =  0.33Poisson's Ratio G11 Tube μ2 = 0.2

Diametral Interference b/w Disc and

, 3OD of Al Disc, d4 =  92mmThickness of Disc/Ring, h 15mm

Poisson s Ratio G11 Tube             μ2   0.2Poisson's Ratio Al 6061T6c Ring μ3 =  0.33

Young's Modulus Al 6061T6 Disc, E1 = 70GpaDiametral Interference b/w Disc and Tube, δi 0.12 mmDiametral Clearance b/w Disc and Tube, δo 0.02 mm

Young's Modulus G11 Tube,           E2 = 28Gpa Young's Modulus Al 6061T6 Ring, E3 = 70Gpa

Friction Coeff b/w Al 6061T6 Disc/Ring , o

l d k b

Friction Coeff  b/w Al 6061T6 Disc/Ring and G11 Tube 0.3

Max Axial Load taken by Inner Joint Fi = 2700 KgMax Axial Load taken by Outer Joint Fo =  2361 Kg

Contact pressure at Inner Joint Pi =  32.8 MPaContact Pressure at Outer Joint Po =  26 MPa

November 2, 2011 41

Prototype Fabrication

30

15

20

25

d; k

N0

5

10

15

Load

00 1 2 3

Displacement; µm

Load Testing of Inner Joint

Result: Prototype has taken load of 26 KN before slippage.

2D Drawings of Support Post Components

November 2, 2011 43

2D Drawings of Support Post Components

November 2, 2011 44

Static Thermal Load (conduction)

As Calculated by keeping the dimensions same as that for HTS-1

2 K InterfaceQ2K

0.004W

2 K

66

23

4 K InterceptQ4K

4 K

22

236 20

80 K Intercept

Q4K

1.2W

300 K

80 K

45

20

40 80 K InterceptQ80K

4W

300K 20

300 K Interface

November 2, 2011 45

8 Cryomodule Component Test Rig8. Cryomodule Component Test Rig

2-Nov-11 46

8. Cryomodule/HTS Component Test Rig

Objective

1. To experimentally validate the design of subsystems like cavity support system and cool down of thermal shield.

2. To experimentally verify newer concept of cavity support system. Specifically verify whether assumptions, boundary conditions etc as chosen were correct. 

Thank YouThank You