FRIB Cryomodule System Design Main Components Allow Modular Procurement And Assembly M. Leitner,...

This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661, the State of Michigan and Michigan

State University. Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

Matthaeus LeitnerSuperconducting RF Department Manager

FRIB Cryomodule System Design

Cryomodule Overview

Detail Cryomodule Interfaces

Cryomodule – Linac Section Interfaces• Front End

• Stripper

• Folding Segments

• Warm Diagnostics Boxes

Summary

Outline

M. Leitner, March 2014 Workshop on Cryomodule Maintenance - 13, Slide 2

Cavity And Cryomodule Count Plus Need For Several Cavity Families Make FRIB Challenging


Cavity TypeQuantity of

Cavities

Quantity of

Modules

Quantity of

Solenoids

β=0.041 12 3 6

β=0.085 88 11 33

β=0.29 72 12 12

β=0.53 144 18 18

Additional

Bunching

Modules

6

4

4

2 (β=0.085)

2 (β=0.29)

1 (β=0.53)

n/a

Total 330 49 69Quant i t ies do no t inc lude 4 spare cryomodules and 17 spare cav i t ies .

FRIB Superconducting Driver LinacLayout is Folded Into Three Accelerator Sections


Driver Linac

≥ 200 MeV/u Oxygen To Uranium

Primary Beam Power on Target: 400 kW

49 (+ 4 Spare) Cryomodules, 330 (+ 17 Spare) Cavities

High Power Accelerator Paired With Significant Operational Flexibility

First FRIB-style Quarter Wave Cryomodule Under Construction: Cavities Operate At 2 K, Solenoids At 4.5 K


FRIB Bayonet Connections

Magnetic Shield

β=0.085 CavitySolenoid

2K Heat Exchanger Cryogenic Piping

Vacuum Vessel Base Plate

Alignment Support

Solenoid Leads

Coldmass Support Rails

ANL RF Coupler

Projected Heat Load Static Dynamic

2 K 4.0 W 32.0 W

4.5 K 20.5 W 2.1 W

38/55 K 167.2 W 33.4 W

Cold Beam

Position Monitor

Cryomodule Main Components Allow Modular Procurement And Assembly


Vacuum vessel

Thermal shield

Cryogenics

Magnetic shielding

Coldmass

Bottom plate

Bayonet box

Alignment adjusters

• Subassemblies procured from industry

• Main assembly performed at MSU

Both Key Coldmass Designs FinalizedDesign and Prototyping Progress Supports Project Baseline


Quarter Wave Resonator Coldmass

Half Wave Resonator Coldmass

β=0.085 Cavity

(operated at 2 K)

Wire Position Monitor

(Alignment Verification)

Solenoid

Vapor-Cooled Leads

SC Solenoid

(operated at 4.5 K)

Power Coupler

Support Rail

β=0.53 Cavity

(operated at 2 K)

SC Solenoid

(operated at 4.5 K)

Support Rail

Power Coupler

Novel Self-Aligning, Kinematic Support-System Has Been Tested During Several Cool-Downs And Functions Consistently At High Repeatability and Accuracy

Alignment of cavities and solenoids stay well within alignment specifications

Optical target measurement results• Cavity alignment

» within +/- 0.003” (0.076 mm) horizontally

» within +/- 0.002” (0.05 mm) vertically

Wire Position Monitor measurements• Cavity alignment

» within +/- 0.003” (0.076 mm) horizontally

» within +/- 0.001” (0.03 mm) vertically

G-10 Posts

With Linear Bearings

Guided pin

Roller Capsule

Cavity mount provides stress-free thermal contraction with significant anti-rocking stiffness – essential for quarter wave resonators

Cavity Sliding System


Heat Treatment Data from Vendor

14 hours

• 1,100 °C Max Temperature

• Cool Down in Inert Atmosphere

FRIB Develops Technical Innovations For Low-Beta Cryomodules

3D Shaped O-RingSeparated Cavity / Cryomodule Isolation Vacuum

Rail Assembly Optimized For Mass ProductionSelf-Aligning Support System

Custom Rail Heat TreatmentFull Stress Relieve To Minimize Distortion During Cool-Down

Reset To Austenitic State (Min. Permeability)


Local Magnetic Shielding is Designed to Keep Resonator Surfaces Below 15 mG When Transitioning to SC


Local Shielding Detail Design Is Based On ReA3 Experiences

FRIB Cavity Tuner Designs Are Finalized Performance Has Been Validated

Stepper Motor

To Cavity Bottom

Tuning Plate

55 K Intercept

Cold Helium Piston Actuator

Support Frame

Tuning Arms

And Cavity

Flange Mount

Tuner TypeQWR

β=0.085HWR

β=0.53

Minimum Tuning Range [kHz] 30 120

Tuning Resolution (2% of Bandwidth) [Hz] 0.8 0.6

Maximum Backlash (5% of Bandwidth) [Hz] 2 1.5

Cavity Tuning Sensitivity (calculated) [kHz/mm] ~ 3.2 ~ 236.2

Maximum Displacement [mm] (*) port-to-port ±7.5 -0.5 (*)

Cavity df/dp (Free Tuner) (calculated) [Hz/torr] ~ -1.4 ~ -3.43

Cavity LFD (Free Tuner) (calculated) [Hz/(MV/m)2] ~ -0.7 ~ -3

Test Status: Operational In ReA3 Cryomodules Test Status: Operation Verified During Integrated Vertical Test

Increased cavity

frequency tunability by

welding “tuning puck” to

tuning plate providing

±30 kHz final tuning

range.

4.5 K Intercept

Cryomodule FlangeTension Cables

Cavity Beam

Port Tuning

Direction


QWR Will Utilize ANL Coupler With Cold Window And 90 Degree Bend,HWR Will Utilize SNS-Style Coupler With Single Warm Window

Coupler TypeQWR

β=0.085HWR

β=0.53

Frequency [MHz] 80.5 322

Line Impedance [Ω] (*) will change to 75 Ω 50 50(*)

Cavity RF Bandwidth [Hz] 40 30

Installed RF Power [kW] 2.5 5

Max. Coupler Power Rating [kW] 4 10

Manual Coupling Adjustment ½ To 2 Times Bandwidth

Coupler Interface 1-5/8” EIA 3-1/8” EIA

Total Heat Load To 2 K At Nominal RF Power [W] 0.13 0.6

Total Heat Load To 4.5 K At Nominal RF Power [W] 1.3 2.7

Total Heat Load To 55 K At Nominal RF Power [W] 7.1 6.2

90 Degree Bend

55 K Cold Window

Adjustable Bellows

With 4.5 K Thermal Intercept

Warm Window

At Cryomodule

Feedthrough

Warm Transition

Cavity Flange

With 4.5 K Thermal Intercept

Single Warm Window

Adjustable Bellows For

Coupling Adjustment

Coaxial Line

With 55 K Intercept

RF Conditioning Teststand


Cryomodule P&ID


Requirements imposed by test plan (design verification) and operation (operating modes) drive specifications for instrumentation

Instrumentation specified for all major systems• Cryo systems (4K & 2K) – thermometry, pressure transducers, level

gauges, heaters, valves

• Thermal shields – thermometry

• Cavities – thermometry, heaters

• Solenoid – flow controller/indicator, thermometry, heater

• Magnetic shielding – thermometry, Hall probes, flux gates

• Support rails – thermometry

• Vacuum vessel – vacuum gauges & valves

• Beamline – thermometry, heaters, vacuum gauges & valves

P&ID includes all instrumentation and control elements

Captured in formal note: M40103-TD-000497 “ReA6-I Cryomodule Instrumentation List”

Instrumentation and P&ID

, Slide 14M. Leitner, March 2014 Workshop on Cryomodule Maintenance - 13

FRIB Complex Cryomodule Cryogenic Circuit


2 K Circuit

(Cavities)

4 K Circuit

(Solenoids, Intercepts)

50-70 K Circuit

(Thermal Shield, Intercepts)

Relief ValvesCryogenic Valves

2K Heat Exchanger

Engineering design per ASME B31.3 process piping code and ASME BPVC, section VIII, division 1.

Designed With JLAB Assistance

Half-Wave Resonators Require Careful Attention To Vibration Isolation

Welded Bellow

Flexible Connections

To Resonators

Once cryogenic circuits are welded, structure will be

lifted off the support rails for vibration isolation.

Tension rods support cryogenic circuits from top of cryostat

vacuum vessel and allow longitudinal contraction.

• Cavities are rigidly connected

to stiff rails but only weekly

linked to cryogenic circuit.

• Ball-bearing cartridges allow

transverse motion due to

thermal contraction.M. Leitner, March 2014 Workshop on Cryomodule Maintenance - 13, Slide 16

Cavities2 K Thermosyphon Circuit


Relief Valves

Redundant Level Sensors

2K Sub-Atmospheric Return

2K Sub-Atmospheric Return

(31-35 mbar)4K Supply

(2.5 – 3.5 atm)

Cavity Supply

Cavity Return

2K Heat Exchanger

2K Additional Volume

With Heater For ControlJT-Valve

Solenoids And Intercepts4 K Thermosyphon Circuits


4K Return

(1.3-1.5 atm)4K Supply

(2.5 – 3.5 atm)

4K Beamline

Intercept

(both sides)

Thermosyphon

Supply Lines

Thermosyphon

Return Lines

Cryogenic

Control Valve

Relief Valves

Solenoid

Return Lines

Rail Connection

(both sides)

Thermal Shield And Intercepts Use50 K Gaseous Forced Flow Circuit


Thermal Shield Is Divided In Three Segments

To Allow For Longitudinal Contraction

• Thermal Shield Segments Are Cooled Utilizing Series Flow

• Couplers Are Cooled Utilizing Parallel Flow

(Design Is An Optimization Between Flow Velocity And Pressure Drop)

Material: 1100 Aluminum For Maximum Thermal Conductivity

Shield Supply: 35 - 45 K, 2.0 - 3.5 atm

Shield Return: 35 - 55 K, 2.0 - 3.5 atm

Coupler Interfaces


Warm Window

Thermal Transition

Elbow

Cold Window

Bellows

Thermal Shield

Cryomodule Vacuum Interfaces


Gate Valve To Beamline

Diagnostics Box

Cryomodule Beamline

Pumping Access During Storage

Cryomodule Beamline

Pumping Access During Storage

Thermal Intercepts Beam Position Monitor

Cold Cathode Gauge

Ion Pump

Maintenance Valve

Interface to Front End


Split into 3 vacuum models:• Pre-RFQ = Extraction Region (ER) + CSS + LEBT

• RFQ

• MEBT (from RFQ exit to first cryomodule in LS1)

Front End (FE)


RFQ

VENUS

Source

ARTEMIS

SourceCSS

LEBT

MEBT

ER

Requirement < 5x10-8 Torr

RFQ is 80.5 MHz copper structure• 5 meters long

• Isolation valves at each end

• Heavy initial conditioning is expected

Pumping through 2 ports per quadrant (8 total)• Pumping requirements are understood

• 8” CF flanges integrated into structure for headers

• 4 – ~700 l/s turbo pumps on headers

• O-rings are used at section joints

• Large, high conductance structure

• Optimization is ongoing

• May require a pump on the RF coupler

Vacuum Layout – RFQ


Requirement < 1x10-8 Torr

MEBT• 4 SC solenoids

• 2 RT bunchers

• 1 RT dipole» Beam dump

• Fast valve

Pumping• 9 – 150 l/s ion pumps (125 l/s used in calculations)

» Pumps applied in an “opportune” fashion

» Standardized on a larger size ion pump due to the bunching cavities* • *Calculations showed the 75 l/s to be too small

» Number may be reduced in final design

Beginning of the particulate free installation near cryomodules

Vacuum Layout – MEBT


Interface to Stripper


Requirement• LS1 < 5.E-9 In the warm regions

Linac Segment 1 Transport Region• 6 diagnostic chambers

» 2 – 47.5 mm

» 4 – 40 mm (included in accelerating systems count)

» All Include 75 l/s ion pumps

Pump and diagnostic chamber added after matching module to protect cryomodule vacuum

Vacuum Layout – LS1 Transport Region


FV


Vacuum Layout – Charge Stripping Area [1]

Part of FS1 in overall design

“Dog Leg”

Vacuum Layout – Charge Stripping Area [2]


Vacuum

requirements

are met

• Requirements (*FRIB Driver Linac Vacuum Requirements)

» 1 x 10-5 Torr in stripper system during operation (from F. Marti)

» < 1 x 10-6 Torr near the Li stripper* (presumed at 1st diagnostic box)

» < 1 x 10-8 Torr near the matching cryomodules* (presumed at or before diagnostic box adjacent to upstream and downstream matching cryomodule)

• Turbo pump Li chamber for pump out; ion pump during Li operation

• Isolation of charge stripper for maintenance and replacement – added valves

• No direct line of sight to matching cryomodules (5 degree dog legs at both ends)

• Fast valves protect cryomodules from a vacuum event in the Stripper

Interface To Folding Segments


Vacuum Layout – FS1


FV

Requirements» FS1 Beam Bending Section < 5.E-8 After the second

45 deg dipole

» FS1 Matching Section < 1.E-8

Folding Segment 1• RT dipoles, quads, and correctors

• 2 beam dumps» BD1-a – 15 w

» BD1-b – 3 kW

• Beam collimator

• 1 matching module (place for additional)

• Beam diagnostics

• 1 fast valve

• 3 isolation valves

Vacuum Layout – FS2


Requirement• FS2 < 1.E-8

Folding Segment 2• SC dipoles

• RT quads and correctors

• 1 matching module

• 1 beam dump

• 2 fast valves

• 3 isolation valves

• 300 l/s ion pump in bends and beam dump line

• 75 l/s ion pump in transport areas

FV

Interface To Warm Diagnostics Boxes


The diagnostic box stand will be developed in final design to utilize common components among other stands following all requirements• Adjustment capability; +/- 1” vertical and +/- ½” in horizontal and longitudinal

• Adjustability to meet the FRIB Driver Linac Placement Requirements which are defined by properly locating the BPM; 0.2 / 0.2 / 1.0 mm

• Temperature» Tunnel temperature is regulated to minimize

movement due to expansion and contraction

of the stands

• Seismic requirements

Diagnostic Box [1]


Ultra-high vacuum due to cryomodule and overall accelerator vacuum requirements• Appropriate fabrication processes enforced and shown on

manufacturing drawings

UHV Cleanroom techniques for assembly/installation• Minimize particulates adjacent to cryomodules

• Draft installation plan completed

Pump down and venting handled by PVS • Portable Vacuum System (PVS) or “pump cart”

Box used 90 times in the accelerator• 57 with 3 3/8” CF flanges and 40 mm I.D. (@ cryomodules)

• 33 with 3 3/8” CF flanges and 47.5 mm I.D. (@ beam transport)

• Includes 65 l/s – 75 l/s ion pump (depending upon type)

• Lower value used for calculations

Diagnostics installed as specified by physics group and detailed in FRIB Parameters List / Lattice File• All installations adjacent to cryomodules have:

» BPM

» Halo Ring diagnostic (design TBD)

Diagnostic Box [2]


Optional

Diagnostic Port

BPM

FV Sensor

Halo Ring

Diagnostic boxes adjacent to cryomodules will be preassembled, prequalified, and baked (as required) prior to installation• Final blow-out and qualification will be done in a

class 100 clean room

Field installation will be done using class 1000 portable clean room sets• 1 for covering work area

• 1 for a prep, gowning, and parts control area

• Minimum of 2 sets required (3 preferable)

• A mock-up will be done as soon as possible to» Validate diagnostic box installation process

» Determine exact clean room size requirements

Diagnostic Box [3]


Proposed portable clean rooms and

layout for installation

FRIB cryomodule interfaces and operational modes are defined

FRIB quarter wave cryomodule P&ID and detail design complete

Until 2015 we will build two prototype cryomodules to validate performance

Summary


FRIB Cryomodule System Design Main Components Allow Modular Procurement And Assembly M. Leitner,...

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