# Presentation: 940018

## ILC Test Facilities

- Sergei Nagaitsev
- Fermilab

## International Linear Collider

- New energy frontier machine proposed for HEP
- Parameters
- Electron-Positron Collider
- Ecm adjustable from 200 – 500 GeV
- Luminosity    ∫*Ldt* = 500 fb-1 in 4 years
- Energy stability and precision below 0.1%
- Electron polarization of at least 80%
- The machine must be upgradeable to 1 TeV

## Overview

- The ILC is based upon a Superconducting Radio Frequency (SRF) linacs of unprecedented scope   ( length=23 km, 1680 Cryomodules, 14,560 SRF cavities, 31.5 MV/m)

- ~30 km

## ILC ML Beam Parameters

| Parameter | Value | Parameter | Value |
| --- | --- | --- | --- |
| Initial Beam energy | 15 GeV | Initial x | 8.4 m |
| Final Beam energy | 250 GeV | Final  x | 9.4 m |
| Particles per Bunch | 2 x 1010 | Initial y | 24 nm |
| Beam Current | 9.0 mA | Final y | 34 nm |
| Bunch Spacing | 369 ns | z | 0.3 mm |
| Bunch train length | 969 s | Initial E/E | 1.5% |
| Number of bunches | 2625 | Final E/E | 0.1% |
| Pulse repetition rate | 5 Hz | Beam phase wrt RF crest | 5o |

- Average beam power is 11 MW / beam  wall plug to beam
- efficiency is crucial  Superconducting RF

## ML basic building block 

- ML basic building block

**ILC RF Unit:**** 3 CM, klystron, modulator, LLRF**

- Baseline design now has 2 CM with 9 cavities, 1 CM with 8 cavities + quad

## Issues for ILC linac

- Key issues for ILC Physics
- Machine Energy, Luminosity, Availability
- Technical Challenges
- Achieving high gradient in SRF cavities with a reproducible process
- Building cryomodules with these cavities that meet ILC specification
- Developing a reliable and efficient RF power source
- Transport and focus beams at the IP
- Industrialization of high volume components
- Cost !
- The Global Design Effort is addressing these challenges via a worldwide R&D program with specific goals (see M. Ross’ talk)
- Key to achieving these goals are evolving ILC Test Facilities, the subject of this talk

## Task Forces

- S0/S1 – Cavity and cryomodule
- S2 – RF unit system tests
- S3 – Damping Rings
- S4 – Beam Delivery System
*S5 – Positron Source*
*S6 – Controls and LLRF *
*S7 – RF sources *

## Major International Test Facilities

- Damping Rings
- ATF, CESR-TA, KEKB, PEP-ii
- S3: Electron cloud; ions; low emittance; kickers
- Main Linac
- FLASH, XFEL, STF, ILC-TA, ESA, Zeuthen
- Rf unit; heat loads; HOM’s; LLRF; rf sources
- S2, S6, S7
- BDS
- ATF2, ESA
- S4: FFS & MDI design; Small spot tuning

## Cavity and Cryomodule Goals

- The GDE has established project wide R&D goals for ILC cavities and cryomodules
- S0 goal: Establish a process & controls to reliably achieve 35 MV/M in bare cavity tests (80% yield)
- S1 goal: Complete an ILC Cryomodule with all cavities at working at accelerating gradients >31.5 MV/M (Average)

## SCRF Infrastructure

- Bare cavities
- Fabrication facilities (Electron beam welder, QC, etc)
- Surface treatment facilities BCP & Electro-polish facilities (EP)
- Ultra clean H20 & High Pressure Rinse systems
- Vertical Test facilities ( Cryogenics + low power RF)
- Cavity Dressing Facilities ( cryostat, tuner, coupler)
- Class 10/100 clean room
- Horizontal Test System (cryogenics and pulsed RF power)
- String Assembly Facilities
- Large class 10/100 clean rooms, Large fixtures
- Cryo-module test facilities
- Cryogenics, pulsed RF power, LLRF, controls, shielding, etc.
- Beam tests  electron source (RF unit test facilities)

## Cavity/CM process and Testing

- Plan... Develop in labs then transfer technology to industry

## Damping Rings

- The ATF at KEK has or will demonstrate many/most of the outstanding issues
- Low emittance operation
- Intra-beam scattering
- Ion instabilities
- Instrumentation development
- Main outstanding issue is the electron cloud
- Studies at PEP-II, KEKB, and CESR
- Very international program

## ATF Prototype Damping Ring

## ATF Prototype Damping Ring

- Ongoing effort with effort from SLAC, FNAL, Cornell, and LBNL
- ATF has been operating since 1997
- Low emittance beams at 1.3 GeV
- Many opportunities:
- Instrumentation and feedback development
- Tuning studies
- Ion instabilities
- Kicker system demonstrations
- Large SLAC involvement since 1992
- Big UK effort with FNAL and Cornell

## Electron Cloud Studies

- Experimental programs at PEP-II and KEKB
- Driven by ILC and Luminosity-factories
- Extensive benchmarking of codes
- Studies of cloud suppression techniques in dedicated vacuum chambers
- Coatings and grooves
- Understanding cloud generation
- No plans for a system test which would need rebuilding the vacuum systems
- System tests at CERN and Frascati

## KEK-B and PEP-II

- Separate problem: calculate instability threshold and electron cloud generation
- Experiments aimed at latter: quantifying techniques to suppress the cloud generation

- KEK-B E-cloud Tests

- PEP-ii Sample test

- PEP-ii Chamber tests

## CESR-TA

- CESR-TA would be a dedicated DR test facility
- Positron beams  testtechniques to suppresselectron cloudgeneration
- Study effect in wigglers whereexpected to bemost important
- Needs further consideration

## Linac Test Facilities

- S0/S1 is coordinating the cavity development
- S2 provided advice on Linac System Tests
- Regional programs: STF, ILCTA-NML, FLASH
- Scoped at the 1 to 2 rf unit level
- XFEL will also demonstrate many systems level issues
- Plans for rf systems tests
- ESA and Zeuthen

## S2 Task Force

## S2 Questions

- Single rf unit tests:
- Check what gradient spread can be handled by the LLRF system.
- Check for heating due to high frequency HOMs.
- Check amplitude and phase stability of the RF with respect to the beam.
- Check static and dynamic heat loads
- Other tests:
- Beam dynamics cannot be tested reasonably
- Statistical effects like reliability and dark current are hard

## DESY R&D Activities

- Cavity R&D
- 9 cell TESLA shape (baseline for ILC)
- Electropolishing development
- Large grain Nb, hydroformed
- Cryomodule  and RF power Development
- TTFII/Flash  ~ RF unit test facility for XFEL
- Industrialization of SRF technology

-     Europe

- The TESLA collaboration centered at DESY developed the SRF technology adopted for ILC. DESY is _the_ world leader

## TTFII/FLASH/XFEL (DESY)

- TTFII/FLASH
- TTFII: was originally a test facility for TESLA (ILC)
- TTFII SRF linac now drives VUV-FEL (FLASH) providing light for BES users
- Machine time still available as ILC test facility
- XFEL (European Project)
- Recently approved for construction at DESY
- 20 GeV SRF linac driven light source
- DESY Facilities (ramping up in support of XFEL)
- Cavity fabrication, processing, test facility upgrades
- Cryomodule fabrication  industrial training for XFEL

-     Europe

## FLASH Overview

- Laser

- RF gun

-     Europe

## FLASH uses TESLA CM’s

-     Europe

## Performance of Recent CM #7

- Recent CM experience
- CM 6 had 5 cavities over 30 MV/M ( but 2 went down WRT HTS)
- CM 7 had 6 of 8 cavities above 30 MV/M ( encouraging)

-     Europe

## TTFII/FLASH

- ILC related performance:
- Operations: 13% unscheduled down time (mostly RF sys)
- Phase stability: 0.14o of 1.3 GHz or 300 fs
- dE/E = 2.4 10-4 measured at 127 MeV
- Plans:
- Add 6th CM, beam energy  1 GeV/c
- Improve electron gun (reduce dark current)
- Add 3rd harmonic CM (FNAL), doubles FEL light output
- FLASH operations, ILC studies, Construct XFEL !!!
- ~30% of time is available for Accel dev and ILC R&D

-     Europe

## XFEL RF Test Facility

## STF (Asia)

- Superconducting Test Facility (STF)
- Location:  KEK, Japan
- Purpose: General SRF test facility in support of the ILC
- Status: Under construction
- Facilities
- Cavity fabrication, processing, test
- ILC module fabrication
- ILC module test facility
- Plan: Evolve into RF unit test facility

-      Asia

## STF Facility

**Cryomodule Assembly**

**EP Facility**

**HPR**

**Klystron Gallery**

**Control Room**

**Refrigerator**

**STF Facility**
**KEK**

**Clean Rooms **

## STF (Superconducting Test Facility)

## STF (Superconducting Test Facility)

## STF R&D Activities ( Asia)

- Cavity R&D
- 9 cell TESLA shape (baseline for ILC)
- 9 cell Ichiro cavities (goal = higher Eacc)
- Seamless cavities (hydroformed)
- Single cell EP R&D
- Cryomodule & RF Power development
- ILC RF unit test facility
- Industrialization of SRF technology

-      Asia

## Cavity R&D at KEK

- 4 Tesla Shape cavities
- Processed and vertical tested
- 3 cavities achieved ~20 MV/m
- 1 achieved 30 MV/m, installed in CM
- Performance limited by field emission

- 4 Ichiro cavities
- Reentrant design lowers B at fixed Eacc
- Single cells: 6 examples all > 40 MV/M
- But... so far 9 cells are only 12-20 MV/M
- Limited by multipacting in end groups
- End groups removed1 achieved 29 MV/M
- One 19 MV/m Ichiro cavity installed in CM

-      Asia

- 40

- EP

## STF Plan 

- STF Plan

**Phase 1 (2005-07)   ****Develop SRF cavities & infrastructure**
**Two types of cavities: TESLA and Ichiro (35 ******** 45 MV/m)**
**Start with two 4 M cryostats (access to STF tunnel)**
**1 cavity in each short cryostat          Now !**
**4 cavities in each short cryostat       Sep 2007**
**Improved cavities                               Apr 2008**
**Phase 2 (2008 – 10) Develop**** ****ILC Main Linac RF unit**
**Built Cryomodule test facility**
**CM Fabrication                                       2009-10**
**Build RF power test infrastructure       now-2010**
**RF unit test                                              2011**
**In parallel with phase 1,2**** **
**GDE S0 task force (demonstrate 35 MV/M gradient)**
**Industrialization**

-      Asia

## Plan of STF Phase 2 beam line

**Plan of STF Phase 2 beam line**

**~36m**

**~65m**

**Toshiba**

-      Asia

**Phase 2 Beam ( 2011)**
**2 SC beam capture cavities**
**RF gun, ( collab with FNAL)**
**Bunch charge, structure, and current similar to ILC**

**Existing Short Cryomodules**

## R&D Activities (Americas)

- Cavity R&D
- 9 cell TESLA shape (baseline for ILC)
- Large grain Nb (TJNL, FNAL)
- Electropolishing (Cornell, TJNL, ANL/FNAL)
- Cryomodule design & fabrication (FNAL)
- RF power development (SLAC)
- ILC RF unit test facility (FNAL)
- Industrialization just starting

## U.S. Cavity R&D = National effort

**Vertical EP **

**Cornell **

**ANL: New clean rooms, **
**state-of-the-art EP**

**FNAL: New Vertical  Test Facility**
**TESTED 1****st**** cavity on 07/24/07**

**ANL/FNAL Collaboration **

**JLab **

**Electropolish **

**Several cavities**
**> 30 MV/m in vertical test **

## VCTF in Industrial Building 1

- Significant cost savings & faster implementation
- Current replacement value ~$10M
- Knowledgeable technical staff
- 4 cryogenic magnet test stands                      FY06: tested 29 superconducting magnets
- 3 conventional magnet test stands                 FY06: tested 21 conventional magnets
- Cryogenic engineering, data acquisition systems, diagnostic instrumentation, software and data management, etc.
- Continue to share cryogenic system and IB1 infrastructure with magnet test program
- Cryogenically demanding LHC magnet production tests are finished

**VTS**
**pit**

- Existing IB1 cryoplant/infrastructure
- for Magnet Test Facility (MTF)

**Notes:**
current cryoplant replacement value (rough estimate) from Tom Peterson: $10 million

In FY06 tested 29 superconducting magnets, including 10 sub-atmospheric [4 LHC quads (3 low-beta), 6 in VMTF (HFM/LARP)], and 19 atmospheric [13 Tevatron magnets, 6 for HINS] not to mention 21 conventional magnets

Point out VMTF, other magnet test stands, offices, footprint of 10-ton crane

Will continue to support magnet testing as a key Lab program .

## VTS Cryostat/Insert Design

**16’**

**heat exchanger**

**phase separator**

**radiation shielding**

**vacuum vessel ********=42”**

**helium vessel 26.5”**

**cavity**

- Based on Fermilab design of DESY/TTF/VTS
- Added phase separator for better quality He

- Cryostat manufactured by PHPK Technologies, Columbus OH

**80K shields**

**5K shield**

**radiation shielding**

**cavity**

**thermal baffles**

**Top plate insert**

**Cryostat**

**fiberglass pit liner**

**Notes:**
Vacuum vessel: 80K shield and intercept cooled by LN2
LN2 supplied from 10000 gallon dewar
GN2 vented to atmosphere

LHe supplied across the roof of IB1 through a transfer line from the 7000 (10000) liter dewar. 

4.5 K phase separator in the cryostat, with liquid level probe and helium vapor vent. A 10W heater is used to control vapor flow.
Phase separator supplies JT heat exchanger with pure liquid, and supplies 5K vapor to cool a thermal shield.
GHe from JT heat exchanger pumped away via Kinney pumps, to be returned directly to compressor suction, or (possibly) vented to atmosphere. 

## Cryostat photos

**September 2006**: Cryostat ordered
**January 2007**: He vessel ASME code stamped
**February 2007**: Received at Fermilab
**March 2007**: Temporarily installed
**April 2007**: Permanently installed
**May 2007**: Cryogenic Safety Review
**May 2007**: First cold test and commissioning
**July 24, 2007:** First single-cell cavity tested!!!

- PHPK

- Fermilab

- Fermilab

## Horizontal Test System (FNAL)

- After vertical test extensive cavity handling ensues
- Cavity welded inside He vessel
- Cavity opened to install main coupler
- Tuner added
- Horizontal Test
- First test of the cavity with high pulsed RF power
- R&D Test bed: tuners (slow), couplers, LLRF, etc.
- NEW HTS facility is nearly complete at FNAL

- “Dressing”

**1.3 GHz Cavity in HTS Cryostat**

**HTS Cryostat**

**RF Power for HTS**

## ILCTA ( FNAL)

- ILC RF unit test facility
- Location: Fermilab “New Muon Building” (NML)
- Goal:  Address the GDE “S2 Goals”
- Demonstrate a complete ILC RF unit with ILC-like beam
- Also crab-cavity R&D, diagnostics development, personnel training, and advanced accelerator R&D.
- ILC-like beam
- 3.2 nC/bunch @3 MHz
- Up to 3000 bunches @ 5Hz
- Bunch length: 300-μm rms
- Injector Energy: 30-40 MeV (to avoid over focusing in ILC CM)
- To understand CM need “known” beam parameters @ CM entrance and exit good diagnostics

## Location

- New Muon Lab

## ILCTA_NM (FNAL) 

- ILCTA_NM (FNAL)

**40-50 Mev Injector**
**Well characterized beam**
**Low energy test area (e.g. 3.9 GHz Crab cavities) **
**New bldg for diagnostics & AARD**
**Also houses new large cryo plant**

- Bunch Compressor

- ILC RF unit

- Diagnostics

- Gun

- CC I,II

- Laser

- 3rd har

- Test Area

- Existing Building

- New Building

- New ILC like tunnel

- 2nd ILC RF unit

- Test Areas

**new 300 W cryo plant**

**RF Equipment**

## Stage 1: 1st CM (early CY08)

- Stage 1: 1st CM (early CY08)

- Capture cavity 2 in its final location for  the injector

- Type 3+ cryomodule

- A used 3 MW Klystron,
- 10 MW, 1.5 ms modulator

- CC2 RF system

## A0 Photo Injector

- The A0 Photo Injector built in collaboration with DESY as part of the TESLA collaboration ( essentially a copy of TTFI)
- In operation since late 90’s
- Two klystron-based RF systems power the RF Gun & Capture Cavity
- Built a second capture cavity (CCII) using high gradient DESY cavity
- A0 RF assets and CCII will be moved to NML in 2008

**RF Gun prior to **
**solenoid installation**

**Capture Cavity and beamline**

**Capture Cavity-II**

## ILCTA Plans

- Effort is Funding limited phased approach
- Cryomodule delivery
- 1st (Type 3+) cryomodule built from “kit” of DESY parts in late 2007
- 2nd (Type 3+) CM –  2008   built with U.S. processed cavities
- 3rd (ILC Type 4) CM – 2009  all U.S. components
- Replace all three CMs with ILC Type 4+ in FY2010
- FY07: Start as a Cryomodule Test Stand
- FY08: move A0 photoinjector, start civil construction for new bldg
- FY09: 1st beam operation, 2-3 CM, low rep rate operations
- FY10: replace all 3 CM with ILC type CM
- FY11: install new refrigerator, ILC RF Unit operations
- Collaboration: DESY, INFN, ANL, Cockroft, NIU, Rochester, KEK

## ILCTA_NML@FNAL

**NML Building**

**NML:  June 07**

**1****st**** of 2 refrigerators**
** ****each 60 W@1.8K**

**FNAL Clean Room**
**& CM assembly Area**

**Parts for 1****st**** CM **
**at DESY**

**Cavities for 1****st**** **
**CM @ FNAL**

## Many groups in the US and world-wide are looking for a place to test their ILC-related designs.

- A facility to test ILC baseline and alternative designs

- Need beam at 200-800 MeV, need space to set up tests
- Baseline design:
- “Keep alive” positron source (ANL)
-  SC undulator (Cornell)
-  Crab-cavity (SLAC, Cockcroft Inst)
- Alternative designs:
- New HOM coupler design (MIT)

## Cryomodule Test Stand

- We know we will need it eventually. ...Need by FY2011
- Location yet undetermined
- A 500 sq meters, 32m x 16m, building required. Includes some utility and access space
- Much larger than a typical Fermilab magnet test stand due to the shielding cave
- Comparable in scope to Stage-1 of NML
- Motivations for cryomodule tests
- Mechanical checks
- Alignment of tubes, flanges, etc.
- Leak checks of all volumes
- Conditioning of main RF-couplers
- Cryo load measurement, Q and Eacc
- SC magnet power test
- Dark current measurements

## XFEL Module R&D Test Stand

**From Yury Bozkho, Bernd Petersen (DESY)**

## SLAC ESA RF Test Facility

- L-Band Test Stands: Existing (green), FY07-08 (blue), FY09 (yellow)

- ESA

- ESB
- (NLCTA)

- LCLS

## Beam Delivery System

- See Andrei Seryi’s talk tomorrow
- The ATF2 at KEK will demonstrate many systems level issues in FFS (and others)
- FFS optical solutions
- Beam instrumentation
- FFS tuning and beam line alignment
- High availability power supplies
- SC quadrupoles
- The ESA is used to study MDI issues
- Collimator wakefields
- IR diagnostics and signals

## ATF2 at KEK

- Demonstrations of:
- Optics design
- RF BPMs
- Magnets and movers
- HA power supplies

- http://lcdev.kek.jp/ILC-AsiaWG/WG4notes/atf2/proposal/public/atf2-web.pdf

- New final focus

- ILC like optics at ATF-2

## End Station A at SLAC

- Collimator design, wakefields (T-480)
- BPM energy spectrometer (T-474)
- Synch Stripe energy spectrometer (T-475)
- IP BPMs, kickers
- EMI (electro-magnetic interference)
- IR Mockup

- 3 runs thus farexpect 3 morethrough FY08
- Schedule beyondFY08 is not clear

## Summary

**The International Linear Collider will employ an SRF linac of unprecedented scope**
**Cavities & Cryomodules are cost drivers for ILC**
**There are many issues to be addressed to demonstrate the required performance for ILC**
**All three regions have mounted large R&D programs to explore these issues**
**Extensive infrastructure is needed to support this R&D and ILC industrialization**
**Large scale RF unit test facilities are a key **
**Lots of progress & ambitious plans**