Global design effort 2007 DOE/NSF review Global design effort Americas Slide 1 April 2007 DOE/NSF ART Review - ILC Polarized Electron Source and Positron Source FY06 Summary, FY07 Status and FY08-09 Proposal WBS 2.3, 3.3, 2.4, 3.4 A. Brachmann and J. C. Sheppard SLAC April 30, 2007

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 2 Nominal Source Parameters ParameterSymbolValueUnits Bunch PopulationNbNb 2x10 10 # Bunches per pulsenbnb 2625# Bunch spacingtbtb 369ns Pulse repetition ratef rep 5Hz Injection Energy (DR)E0E0 5GeV Beam Power (x1.5)PoPo 300kW Polarization e-(e+)P80(30)%

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 3 DOE/NSF FY07 Review Polarized Electron Source – ART FY06/07 Summary FY08/09 Planning (A. Brachmann, SLAC)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 4 Polarized Electron Source WBS Overview WBS 2.3Design WBS 3.3R&D WBS Source Laser R&D WBS Polarized Gun Development WBS Photocathode Development

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 5 Polarized Electron Source FY06/07 Summary WBS 2.3 Source design (beam dynamics simulations) to support injector layout (RDR level)  Electron Gun  Bunching System  NC/SC acceleration  eLTR with Spin precession/rotation  RF energy compression

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 6 Polarized Electron Source FY07 Summary WBS Source laser system design  Completed facility  3 MHz pulse train generation using a modelocked Ti:sapphire laser  Start pulse train amplification work

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 7 Polarized Electron Source FY07 Summary WBS Photocathode R&D  Gridded Photocathodes (external bias for QE and polarization enhancement)  Development of Faraday rotation experiment to study depolarization mechanism  Alternative materials GaN, InGaP/GaAs Superlattice  Atomic hydrogen cleaning system development

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 8 Polarized Electron Source FY08/09 proposal – WBS Design Polarized electron source design Focus is EDR –Subsystem design and engineering –Laser/Gun/Photo-cathodes strongly related to outcome of R&D program –Trans-relativistic region Design is at stage of complete Parmela/MAD/Elegant simulations Engineering and system integration part of the EDR project phase –5 GeV booster linac assumes copy of linac technology  no extra effort in FY08/09 –LTR design is shared between e- and e+  shared effort

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 9 Polarized Electron Source FY08/09 proposal – WBS Laser Development FY 08 –Main R&D Program is the Development of the Amplifier High power cw pump laser and regenerative cryo-cooled Ti:Sapphire amplifier stage FY09 –Complete Amplifier –Address technical challenges –Use laser system and (existing SLC) gun to generate polarized e- bunch train

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 10 Polarized Electron Source FY08/09 proposal WBS – Gun Development Project will receive first ILC funding in FY08 Use resources at Jlab to develop gun technology Min 140 kV operating voltage (200+ kV design) Combine features of SLC and JLAB gun (HV Design/Power Supply/Loadlock) Testing can be done at JLAB and/or SLAC

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 11 Polarized Electron Source FY08/09 proposal WBS – Injector Development –Trans-relativistic region (bunching and pre- acceleration) Variety of reference points (SLAC, NLCTA, TTF, …) Many system are common with e+ source –FY08/09 program (EDR) Transform simulations for L-band bunching into hardware design Evaluate need for prototype of beta matched L-band TW buncher  modified 4.3 m L-band structure (used for e- and e+)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 12 Polarized Electron Source FY08/09 proposal WBS – Photocathode R&D –Strained-superlattice GaAs-GaAsP Polarization = 85 – 90 % Charge limit (problem for SLC/NLC) has been overcome by high gradient doping, however, at expense of polarization For ILC bunch charge is less, hence re-optimization of structure can lead to higher polarization (~ 5%) –Alternative materials: AlInGaAs/GaAs (Ioffe (St. Petersburg, Russia) results: 92 % Polarization) Large bandgap materials GaN, InGaN, AlGaN (robust and high QE) –R&D (ongoing): Investigate depolarization mechanisms (Faraday rotation) –Additional Projects and Activities: Cathode Test System (CTS) upgrade – Polarimeter, Cryogenic capabilities, Use of Surface Science (XPS, SEM, etc.)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 13 Regional distribution of ILC e-source design and R&D Americas –SLAC, JLAB Asia –Polarized source R&D at Nagoya is in transition stage (most likely it will disappear in the near future) –KEK may pick up polarized source R&D Europe –Various polarized source R&D programs and users Mainz, Bonn, St. Petersburg –No direct involvement with ILC

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 14 Budget WBS x.3 Electron Sources FY08: k$ 1,400 FY09: k$ 3,000 WBSFTE FY 08 / 09 Total [k$] (Incl. M&S + Indir.) FY08 / Design1.50 / / Laser Development0.25 / / Gun Development0.75 / / Injector Development0.50 / / Photocathode0.37 / / 400 Budget is adequate for anticipated Program

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 15 DOE/NSF FY07 Review ILC Positron Source – ART FY06/07 Summary and Status FY08/09 Planning (J. Gronberg, LLNL and J. C. Sheppard, SLAC)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 16 Positron Source Layout

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 17 FY06/07 Summaries Developed and promulgated ILC Positron System design for RDR “Optimized” overall layout with respect to function, risk, and cost Documented by writing ILC Positron System RDR chapter Formalized international ILC Positron Collaboration (RAL/06, IHEP/07, ANL/07 Meetings) EDR organizing and planning (ILC S5, see O. Napoly ILC MAC talk 04/07)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 18 ILC Positron Source FY07 Status WBS 2.4. Source Design  Systems Design (production, capture, optics, collimation, accelerators, remote handling, systems specifications, start-to-end simulations)  Monitoring and Planning of R&D Activities: domestic and international (targets, OMD, undulator, Collaboration and S5 coordination)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 19 ILC Positron Source FY07 Status WBS 3.4. Positron Source R&D  LLNL target design for UK developments and test program  Cornell undulator development activities  ANL pulsed flux concentrator (OMD) tests; eddy current modeling for spinning target  SLAC NC SW RF Structure prototyping (C. Adolphsen)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 20 US Institutions Institutions doing substantial work on ILC e+ development –SLAC overall coordination & leadership define parameters target hall, remote handling, activation beamline optics and tracking NC L-Band accelerator structures and RF systems Experiments – E166, FLUKA validation experiment –LLNL target simulations (thermal hydraulics and stress, rotodynamics, materials) target design (testing and prototyping) pulsed OMD design –ANL optics tracking OMD studies eddy current calculations –Cornell undulator design, alternative target concepts

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 21 European Institutions Institutions doing substantial work on ILC e+ development –CCLRC-Daresbury undulator design and prototyping beam degradation calculations –CCLRC-RAL remote handling eddy current calculations target hall activation –Cockcroft and Liverpool University target design and prototyping –DESY-Berlin target hall activation spin preservation photon collimation E166

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 22 Positron Source WBS Overview FY08/09 WBS 2.4Design WBS 2.4.1EDR WBS 2.4.2Systems Engineering WBS 2.4.3Civil Facilities Systems Coordination WBS 2.4.4System Modeling WBS 2.4.5Remote Handling WBS 3.4Research and Development WBS Undulator WBS Target WBS Optical Matching Device WBS 3.4.4Normal Conducting RF Structures

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 23 Budget WBS x.4 Positron Source FY08: k$ 2543 FY09: k$ 5304 WBSFTE FY 08 / 09 Total [k$] (Incl. M&S + Indir.) FY08 / Design5/ / Undulator, UK0.2 / / Undulator, Cornell1/1226/ Target1.3/ / OMD0.5 / /1567

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 24 Select Positron References, 1 ILC RDR Positron Chapter: sec. 2.3, pg. 45 ff ILC Positron Source Collaboration Meetings 1 st meeting at RAL September, 2006: 2nd meeting at IHEP, Beijing January, 2007 : ILC Notes 1. ILC Target Prototype Simulation by Means of FEM Antipov, S; Liu, W; Gai, W [ILC-NOTE ] 2. On the Effect of Eddy Current Induced Field, Liu, W ; Antipov, S; Gai, W [ILC-NOTE ] 3. The Undulator Based ILC Positron Source: Production and Capturing Simulation Study – Update, Liu, W ; Gai, W [ILC-NOTE ] Other Notes 1. F.Zhou,Y.Batygin,Y.Nosochkov,J.C.Sheppard,and M.D.Woodley,"Start-to-end beam optics development and multi-particle tracking for the ILC undulator-based positron source", slac-pub-12239, Jan F.Zhou,Y.Batygin,A.Brachmann,J.Clendenin,R.H.Miller,J.C.Sheppard,and M.D.Woodley,"Start-to-end transport design and multi-particle tracking for the ILC electron source", slac-pub-12240, Jan A.Mikhailichenko, " Liquid metal target for ILC*."*. Jun pp. Prepared for European Particle Accelerator Conference (EPAC 06), Edinburgh, Scotland, Jun Published in *Edinburgh 2006, EPAC*

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 25 Select Positron References, 2 Other Notes, cont’d 4. A.A. Mikhailichenko, "Test of SC undulator for ILC.",Jun pp. Prepared for European Particle Accelerator Conference (EPAC 06), Edinburgh, Scotland, Jun spires.slac.stanford.edu/spires/find/wwwhepau/wwwscan?rawcmd=fin+%22Mikhailichenko%2C%20A%2EA%2 E%22 Published in *Edinburgh 2006, EPAC* A.Mikhailichenko, "Issues for the rotating target", CBN-07-02, 2007, A.Mikhailichenko, "Positron Souse for ILC:A perspective", CBN-06-06, 2006,

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 26 Electron and Positron Sources End of Formal Presentation Additional info as needed

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 27 Positron Plans Backup and Breakout Discussion Slides

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 28 FY 06 WBS Photocathode R&D - Biased Photocathodes (SBIR with Saxet Inc.) Biased photocathodes (thin unstrained GaAs) – Bias across Photocathode using metal grid – forward bias  QE ↑ – negative bias  QE, Polarization ↓

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 29 Major Issues Target design, prototyping needed –integrity target spinning mechanical effects pulsed OMD thermal stress cooling design activation and radiation damage –vacuum, water couplings –eddy current heating effects –target hall remote handling OMD –baseline is pulsed because we do not completely understand effects of DC magnetic field on target Beam loss in beamlines –collimation schemes Undulator prototyping needed to ensure specs are met

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 30 Meetings Regular meetings –10.30AM (PST) Wednesdays - positrons ANL, LLNL, SLAC,Cornell Alternate between hardware issues and optics Maybe expand the invitation list –08.00 AM (PST) Thursdays - target SLAC, Daresbury, RAL, DESY-Z, ANL, LLNL Alternate between target design & hall activation –08.00 AM (PST) Wednesdays – E166

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 31 Positron RDR Update Positron RDR, in good shape –Numbers need to be checked and finalized –Figures are fine, one or two could be even better –April 1 deadline for complete RDR draft –June or so for non-draft RDR & paper version EDR plans being hatched.. E166 getting closer to publishing!!!

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 32 Positron Collaboration Meeting ILC Positron Source Collaboration Meeting –Collaboration to meet three times a year 1 st meeting at RAL last November Main web page: –2 nd meeting in Beijing before GDE meeting Main web page : Summaries: –19 attendees, USA-Europe-Asia, 2 from SLAC : John & Feng)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 33 A. Target Systems(I. Bailey/ T. Piggott) Source alternative magnet solutions for first proposed UK target prototype - Ian B to coordinate. LLNL to evaluate DL target prototype design for vibrational modes and compatibility with water-cooling design (flow rates, etc) - Tom P to coordinate. Rationalise proposed UK prototyping wrt available funding - Ian B to coordinate. Continue evaluation of alternative target materials - Chris D to coordinate. Seek further clarification from BINP on their 1ms OMD work - Vinod B to coordinate. Adopt common geometry for eddy current simulations (based on UK prototype?) - Jeff G to coordinate. Beam window issue remains unresolved? Wei + Alexander to discuss. Topic Action Items: Target Summary

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 34 Target Wheel

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 35 Topic Action Items: D. Target Hall (I. Bailey on behalf of V.B.) Evaluate dose rates for short times after shutdown (1 hour, 1 day) - Andriy (DESY) Complete detailed target station geometry for FLUKA - Luis (DL) Include material absorption effects in FLUKA simulations - Andriy (DESY) Carry out benchmarking of FLUKA using Ti alloy at SLAC - John (SLAC) Get feedback on impact of 53 hour changeover on availability - Vinod (SLAC) Evaluate need to include photon collimator in remote-handling module - Lei (Liverpool) Evaluate activation of water in water-cooled systems - Andriy (DESY) Evaluate shielding requirements compatible with 53 hour remote-handling schedule - Andriy (DESY) Evaluate achievable vacuum. Assess need to evolve pillow seal design. - Ian (Liverpool) Does ILC plan to have a central hot cell facility? - Vinod (SLAC) Develop detailed remote-handling scenarios - Mike W (RAL) Assess need for remote-handling for KAS - Vinod (SLAC) Target Hall Summary

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 36 Target Remote Handling Estimated 53 hour replacement time

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 37 Optical Matching Device (OMD) Optical Matching Device –factor of 2 in positron yield (3 if immersed target) –DC solenoid before target or pulsed flux concentrator after target –Pulsed device is the baseline design Target spins in the magnetic field of the OMD –Eddy currents in the target – need to calculate power –Magnetic field is modified by the eddy currents – effect on yield?? Eddy current mitigation –Reduce amount of spinning metal –Do experiment to validate eddy current calculations –Look for low electrical / high thermal conductivity Ti-alloys –Other materials such as ceramics –No OMD Use focusing solenoidal lens (1/4 wave) – lower fields OMD is upgrade to polarization!!!!!

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 38 Eddy Current Experiment Eddy current calculation mesh - S. Antipov, W. Liu, W. Gai - ANL Proposed experiment Layout at Cockcroft Institute/Daresbury (this summer)

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 39 Calculated Eddy Current Power Nominal RPMs

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 40 Target Progress Baseline target/capture –RAL, ANL and Cornell have done Eddy current simulation which produce consistent results with multiple codes. Estimates for power dissipation in the target are >100kW for a constant field and are considered excessive. –Evaluation of ceramic target material is on-going. No conclusions. –Radiation damage of the superconducting coil is still TBD but may not be worthwhile unless a solution can be found for the eddy currents. –ANL simulation of beam heating in windows shows that an upstream window is feasible but a downstream window is not. Alternative target/capture –Capture efficiency for the lithium lens focusing and ¼ wave solenoid is still TBD –Thermal heating and stress for the lithium lens is still on-going. –Thermal stress calculation for the liquid metal target is still on-going

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 41 OMD Plans and Actions (baseline target/capture): –ANL will simulate eddy currents in the pulsed magnet configuration. –UK will evaluate suitability of non-conducting materials for the target –Daresbury/Cockroft/RAL will spin a one meter target wheel in a constant magnetic field and will measure the forces. Eddy simulations will be calculated and benchmarked against this configuration Plans and Actions (alternative targets/capture): –ANL will determine the capture efficiency for ¼ wave focusing optics and lithium lens. –LLNL will evaluate the survivability of lithium lens to beam stress –Cornell will specify an initial design of a liquid metal target. LLNL will calculate the Stress-strain behavior of the outgoing beam window.

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 42 Optics Source optics laid out. Need to look at details –Beam loss and collimation –Component interferences (target halls, DR injection) –Refine and document optics and beam physics

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 43 FLUKA Validation Experiment

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 44 FLUKA Validation Experiment SLAC/CERN Collaboration (RP groups) –Validation of FLUKA activation calculations 100 W 30 GeV electron beam in ESA at SLAC Cylindrical copper dump Samples around the dump (including a Ti-4V- 6Al) Look mr/hour and gamma spectrum from irradiated samples –Run at the beginning of April …

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 45 Experiment Setup

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 46 Preliminary Data: Ti and Ti-alloy

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 47 STATUS OF CORNELL UNDULATOR PROTOTYPING Alexander Mikhailichenko, Maury Tigner Cornell University, LEPP, Ithaca, NY A superconducting, helical undulator based source has been selected as the baseline design for the ILC. This report outlines progress towards design, modeling and testing elements of the needed undulator. A magnetic length of approximately 150 m is needed to produce the desired positron beam. This could be composed of about 50 modules of 4 m overall length each. This project is dedicated to the design and eventual fabrication of one full scale, 4 m long undulator module. The concept builds on a copper vacuum chamber of 8 mm internal bore

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 48 Fig.1;Extensible prototype concept for ILC positron undulator. Diameter of cryostat =102mm

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 49 Undulator cold mass design Fig.2:Details of design. 1–Iron yoke, 2–Copper collar, 3, 4–trimming Iron nuts. Inner diameter of Copper vacuum chamber is 8mm clear.

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 50 Several 40 cm long undulator models with 10 and 12 mm period, Ø 8 mm clear bore have been made and measured. See Table OFC vacuum chamber, RF smoothness For aperture diameter 5.75 mm we expect: for period 8mm – K~0.4 ; for period 10mm -K~0.9 SC wire54 filaments56 filaments # layers5* 6* 9** (12***) +sectioning λ=10 mmK=0.36 testedK=0.42 tested K≈0.5 (calculated) λ=12 mmK=0.72 testedK=0.83 testedK≈1 (calculated) *) Wire – Ø0.6 mm bare; **) Wire – Ø0.4 mm bare; ***) Wire – Ø0.3 mm bare Fig.3: Field profile – conical ends. 6 layer, 12 mm period – orthogonal hall probes. 1Tesla full scale

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 51 Progress to Date An overall concept design for the module as shown in Fig. 1 has been developed. The design is very compact, having an outside cryostat diameter of 100 mm. Standard size plumbing components are used throughout. Figure 1 shows the cross section design for tapered end coils. We have made optimization studies for undulators having 10 and 12 mm period with 8 mm clear bore and wound with various commercially available wires. Technology for fabrication of the undulator has been reduced to practice including winding of the wire and the helical iron yoke as well as procedures and apparatus for measuring the field distribution at the operating temperature. Several 40 cm long undulator models with 10 and 12 mm period, 8 mm clear bore have been made and measured.

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 52 Summary Page for the Capture RF Topic Action Items: C.Capture RF 1.Progress Five-cell L-Band SW Test Structure Microwave QC for all accelerator cells and assemblies has been completed. As a last assembly, the coupler assembly has been delayed. Now the final machining for cell profile is nearly finished. We plan to have a stack measurement starting from next week. The final structure assembly will be done in February of Then, the microwave tuning, characterization as well as high power test will proceed. L-Band RF Windows Two windows have been completed and are under high power test. All of other three sets of window parts are ready to assembly. 2. In the process of cost estimation and drafting for RDR, the RF system configuration and detailed parts count have been carefully studied. Juwen Wang

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 53 Prototype Positron Capture Section

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 54 Preliminary Microwave Checking MHz at 20°C, N MHz at 20°C, N 2 Field Plots for Bead Pulling Two Different Frequencies Showing the Correct Cell Frequency and Tuning Property. Measurement Setup for the Stacked Structure before Brazing without Tuning

Global design effort 2007 DOE/NSF review Global design effort Americas Slide 55 Brazed Coupler and Body Subassemblies Ready for Final Brazing