Beam Delivery and MDI R&D Andrei Seryi, SLAC ILC DOE review April 4 -6, 2006
Topics covered and not (from Gerry’s list) beam delivery and MDI R&D 2. 10, 3. 10, 5. 10. 2 Seryi (SLAC) 2. 10. 1 beam delivery system design SLAC Seryi 5. 10. 2 ESA Beamline Instrumentation Upgrade SLAC Woods 3. 10. 1 ESA BPM Precision Tests - T 474 3. 10. 1. 2 ESA Collimator wakefield Tests - T 480 SLAC 3. 10. 1. 3 ESA Synchrotron rad. spectrometer - T 475 3. 10. 2 ATF 2 Cavity BPM Electronics 3. 10. 3 M&S K$ ESA BDS/MDI Experiments 3. 10. 1. 1 FTE 5. 3 0 1. 66 169 Tenenbaum 0. 3 0 SLAC Ross 1. 4 42 Nanometer resolution BPM system LLNL Walston 0. 22 20 3. 10. 7 2_04: RF Beam Position Monitors for Measuring Beam Position and Tilt UCB Kolomensky 3. 10. 4 Final focus quadrupole full length coil BNL Annerella 1. 75 25 3. 10. 5 Conceptual design work BNL Parker 1. 75 0 3. 10. 6 Beam delivery system-collimators FNAL Mohkov 1 50 3. 10. 8 2_26: Continuing Research and Development of Linac and Final Doublet Girder Movers Colo. State Warner Covered in the talk of Marc Ross “R&D at international test faciltiies (TTF, ATF 2)” 2 4 Apr 06
BDS design (2. 10. 1) • Optics of final focus, collimation and extraction lines, methods of tuning, etc • Interaction regions design, background simulations • Beam dumps, collimators • IR hall shielding • Crab cavities • Conventional facility layouts of BDS • Simulations of feedback for BDS, developments of prototypes for tests at ATF/ATF 2 3 4 Apr 06
Baseline layout 20 mrad IR and 2 mrad IR • Two longitudinally separated IPs, two independent collider halls for two experiments • Grid size: 100 m * 5 m 4 4 Apr 06
Next few slides illustrate details of layouts and corresponding optics M. Woodley, Y. Nosochkov, P. Raimondi, A. Seryi, et al EFF 1 5 EDL 1 4 Apr 06
EBSY skew correction polarimeter chicane EIRT 1 EIRT 2 MPS betatron collimators kicker, septum 4 -wire 2 D e diagnostics Energy diag. chicane betatron collimation to IP EFF 2 EBSYD High bandwidth horiz. bending system EFF 2 EFF 1 EBSY 6 to tune-up dump to IP 4 Apr 06
betatron collimation EIRT 2 EFF 2 energy collimation energy spectrometer to IP EIRT 1 EFF 1 EIRT 2 to IP 7 4 Apr 06
PDL 2 EFF 2 aberration correction section E and polarization diagnostics EDL 2 PFF 2 EDL 2 final transformer EFF 1 disruption beam capture tail folding octupoles 8 PDL 1 E and polarization diagnostics 4 Apr 06
Beam dumps & collimators • ILC Beam dump design based on design of MW dumps established at SLAC in sixties by D. Walz • Adjusted design for 18 MW • Working with collaborating labs (UK) on eng. design and cost estimate for RDR Picture of beam dump from NLC 1999 study D. Walz, E. Doyle, T. Markiewicz, L. Keller, et al • Collimators: experience in design of survivable and renewable spoilers • Plan survivable spoilers for ILC, will build renewable for LHC (experience may then be Collimators (spoilers, absorbers). applied to ILC) Spoiler: ~1 r. l. of Cu, and Cu plated Be to min 9 wakes 4 Apr 06
IR design • Design of IR for both small and large crossing angles • Optimization of IR, masking, instrumentations, background evaluation • Design of detector solenoid compensation B. Parker, Y. Nosochkov, T. Markiewicz, C. Spencer, SLAC-UK-France task force, et al 10 T. Maruyama et al 4 Apr 06
IR & radiation safety 1) Hall with shielding wall 18 MW loss on Cu target 9 r. l at s=-8 m. No Pacman, no detector. Concrete wall at 10 m. Dose rate in mrem/hr. • For 36 MW MCI, the concrete wall at 10 m from beamline should be ~3. 1 m Alberto Fasso et al Wall 25 rem/hr 10 m 11 4 Apr 06
2) Self-shielding detector A proper pacman can reduce dose below 25 rem/hr Desired thickness is in between of these two cases 18 MW on Cu target 9 r. l at s=8 m Pacman 0. 5 m iron and 2 m concrete 18 MW on Cu target 9 r. l at s=-8 m Pacman 1. 2 m iron and 2. 5 m concrete color scale is different in two cases 18 MW at s=-8 m: Packman Fe: 0. 5 m, Concrete: 2 m Fe: 1. 2 m, Concrete: 2. 5 m 12 dose at pacman external wall 120 rem/hr (r=3. 5 m) 0. 65 rem/hr (r=4. 7 m) dose at r=7 m 23 rem/hr 0. 23 rem/hr 4 Apr 06
Self-shielding (cont. ) Illustrate two designs os the “tunnel plug” In the first one there is not enough overlap of shielding in the tunnelhall transition 0. 5 -0. 7 m of Fe for last 5 m of tunnel; 0. 5 m transverse Fe shielding in Pacman Iron next iteration of design show satisfactory performance Proper “tunnel plug” can be designed 13 color scale is different in two cases 4 Apr 06
CF BDS layouts: example of e+ transport options e+ tunnel baseline solution abandoned version F. Asiri, C. Corvin, et al. 14 abandoned version 4 Apr 06
3. 9 GHz Crab Cavity (FNAL Design) Omega 3 P Mesh HOM coupler Input coupler SOM coupler LOM coupler Collaboration is being formed to work on ILC crab cavity systems: Fermilab, Daresbury, SLAC. The 3. 9 GHz deflecting cavity designed at Fermilab. Several simplified models built. Complete design with all couplers exist and is being verified/optimized, and then a prototype will be built. Phase stabilization system is being designed. 15 4 Apr 06
Qe of Modes in the 3. 9 GHz Crab Cavity “Omega 3 P Preliminary Results” Operating mode • Parallel codes capable of simulating complex 3 D cavities in time and frequency domains were applied to the optimization of HOM damping in ILC Low-Loss cavity. These capabilities are now applied to the design of the 3. 9 GHz crab cavity. K. Ko, Z. Li, et al 16 4 Apr 06
ILC Beam Tests in End Station A Collimator design, wakefields (T-480) BPM energy spectrometer (T-474) Synch Stripe energy spectrometer (T-475) Linac BPM prototypes IP BPMs/kickers—background studies EMI (electro-magnetic interference) Bunch length diagnostics Mike Woods, Ray Arnold in “SLAC Today” news Parameter SLAC ESA ILC-500 10 Hz 5 Hz Energy 28. 5 Ge. V 250 Ge. V Bunch Charge 2. 0 x 1010 Bunch Length 300 mm Energy Spread 0. 2% 0. 1% Bunches / train 1 (2*) 2820 Bunch spacing - (20 -400 ns*) 337 ns Repetition Rate 3. 10, 5. 10. 2 http: //www-project. slac. stanford. edu/ilc/testfac/ESA/esa. html PAC 05 paper/poster: SLAC-PUB-11180, e-Print Archive: physics/0505171 CCLRC QMUL U. of Bristol UMass Amherst CERN Lancaster U. SLAC UC Berkeley U. of Oregon DESY 17 LLNL Manchester U. TEMF TU Darmstadt U. of Cambridge KEK Notre Dame U. of Birmingham UCL *possible, using undamped beam 4 Apr 06
T-480: Collimator Wakefields 3. 10. 1. 2 Collimators remove beam halo, but excite wakefields. Goal is to determine optimal collimator material and geometry. These studies address achieving the ILC design luminosity. PIs: Peter Tenenbaum (SLAC), Nigel Watson (U. of Birmingham, UK) Collaborating Institutions: U. of Birmingham, CCLRC-ASTe. C + engineering, CERN, DESY, Manchester U. , Lancaster U. , SLAC, TEMF TU 18 Collimator wakefield box moved from Sector-2 to ESA. 2 sandwiches, each holding 4 collimators, available. Collimators being provided by UK groups. Wakefield kick angle measurements provided by T-474 BPMs. 4 Apr 06
T-474, 475: Energy Spectrometers 3. 10. 1. 1, 3. 10. 1. 3 Precision energy measurements to 50 -200 parts per million are needed for Higgs boson and top quark mass measurements. BPM and synchrotron stripe spectrometers will both be evaluated in a common 4 -magnet chicane. These studies address achieving the ILC precision measurement goals. T-474 PIs: Mike Hildreth (U. of Notre Dame), David Miller (UC London, UK) T-475 PI: Eric Torrence (U. of Oregon) Collaborating Institutions: U. of Cambridge, Collaborating Institutions: SLAC, U. of Oregon DESY, Dubna, Royal Holloway, SLAC, UC Berkeley, UC London, U. of Notre Dame • prototype quartz fiber detector (8 100 -micron • Initially, will use SLAC Linac BPMs. New fibers + 8 600 -micron electronics based on nanobpm work at KEK, fibers w/ multi-anode being developed by UC Berkeley. PMT readout) is installed • New BPMs will be designed at UC London at A-line SLM (synch lite in collaboration with SLAC experts Monitor) location. • Will test ILC Linac BPMs being developed by C. Adolphsen and G. Bowden 19 4 Apr 06
ESA runs in 2006 January 2006 Commissioning Run Collimator wakefield box Wire Scanner • ESA running in FY 06: – T-469: Nov. 16 -18, 2005 (using secondary beams from Be target in Linac) • ILC T-474, T-475, T-480: – – 20 i) Commissioning run – January 4 -9, 2006 ii) April 24 – May 8, 2006 iii) July 3 -17, 2006 ANITA Test Beam? 2 weeks in June possible ESA plans for running in FY 07 -08: at least two 2 -week runs each year, for ILC tests 4 Apr 06
January 2006 Commissioning Run Alcove rf BPMs (3 sets of bpm processors to analyze data) 21 100 GHz Bunch Length Detector 4 Apr 06
ESA Equipment Layout, Layout including a future 4 -magnet chicane 3. 10, 5. 10. 2 18 feet Jan. 2006 commissioning run: i) 3 WAKE 1 (T-480), 3 WS 1 and 3 C 2 were installed ii) T-474: new BPM electronics were commissioned with existing BPMs iii) T-475: prototype detector commissioned at A-line SLM location iv) new bunch length diagnostics commissioned with rf detectors at a ceramic gap in ESA March 2006: 2 SPEAR girders, 3 BPM 3 -5 (Linac rf BPM prototype), 3 WS 2, 3 BPM 9 -11 were installed 22 4 Apr 06
Linac rf BPM Prototypes -Triplet on the girder. Installed two girders with 1 wire scanner and 2 bpm triplets onto the beamline last week 3. 10. 1. 1 girders before installation girders installed 23 4 Apr 06
IP BPMs/Kickers—background studies Use “spray” beam with Be Target at end of Linac to generate similar flux density and momenta as collision pair background. Measure sensitivity to backgrounds, EMI. Plan to submit test beam proposal ~Feb. 1. (U. of Oxford, SLAC) EMI Studies • Plan to characterize EMI along ESA beamline using antennas and fast scopes, in frequency range from 10 k. Hz to 2. 5 GHz • Measure dependence on bunch charge, bunch length • $14 K available from US-Japan funds for FY 06 (KEK, SLAC) 24 4 Apr 06
Other Tests being discussed: 1. BPM test stations 2. Bunch length and longitudinal profile measurements – electro-optic, Smith-Purcell, coherent transition radiation, other? – Initial measurements are using rf detectors at a ceramic gap in a few frequency bands from 10 GHz-100 GHz – 300 -micron ILC bunch length is same as LCLS after 1 st bunch compressor – ESA is a good place to commission diagnostics for this 3. Spray beam or fixed target to mimic pairs, beamsstrahlung, disrupted beam – for testing synchrotron stripe energy spectrometer, IP BPMs, BEAMCAL 4. Material Damage studies – For spoilers, need to determine optimal geometry and material – Study dependence on bunch length in range 100 -500 microns 5. IR Mockup? – Mimic beamline geometry at IP within ± 5 meters in z and ± 20 cm radially 6. Single Particles (electrons, photons, pions) – 1 -25 Ge. V particles with 1 or less particles/bunch at 10 Hz for ILC Detector tests 25 4 Apr 06
ESA, costs • i) Budget: $100 K M&S, $100 K shop, 2. 8 FTEs for SLAC labor • ii) Actuals thru end of February (ie. 5/12 months to calculate pro-rating for labor FTEs, assuming $130 K/FTE): – $47 K M&S, $48 K shop, 3. 7 FTEs (3. 7 FTEs based on $198 K SLAC labor for 5 months) • This program is planned to continue into FY 07 and FY 08, and runs parasitic with PEP-II. • The FY 07 prelim budget submitted in February was $77 K M&S, $103 K shop and 2. 7 FTEs. • Running beyond FY 08 and the PEP-II program is being studied, and would require an investment of $500 K to replace the PPS (personnel protection system). 26 4 Apr 06
ILC Final Focus Magnet R&D - FY 06 3. 10. 4, 3. 10. 5 The main conceptual design activity in FY 06 has been the development of the “smaller” large crossing angle IP. The original 20 mrad crossing angle proposal resulted in asymmetric and (somewhat) larger detector backgrounds. The 20 mrad is determined by the size of the superconducting coil cross section. In Snowmass the request was made to develop a large crossing angle (defined as a separate incoming and outgoing beams) which was as small as possible (sic). To this end the design of a 14 mrad solution has been initiated The minimum angle is achieved when the outgoing beam pipe is as close to the final focus magnet as possible. This resulted in magnetic cross talk which has required the development of actively shielded compact (direct wind) coil designs within a common cryostat 27 4 Apr 06
ILC Final Focus Magnet R&D - FY 06 A Nb-Ti coil X-section with a 66 mm OD will meet the 144 T/m design gradient. Outgoing beam pipe is ~ 4 mm beyond the shield coil. All components are housed in a common cryostat. Magnet operates at 1. 8 K 28 4 Apr 06
ILC Final Focus Magnet R&D - FY 06 QT (test coil) cross section Since this an unproven magnet concept a major goal of the FY 06 R&D program was the fabrication and testing of a short (20 cm) proof of principle coil. The quad X-section was as desired but no correction coils and the shield coil was wound onto a separate tube 29 4 Apr 06
ILC Final Focus Magnet R&D - FY 06 The results were encouraging: Operating parameters: 144 T/m with 3 T solenoid background < 10 units unwanted harmonics (10 -4 at 10 mm) • QT reached “short sample” with only two training quenches (both of which were above Iop). • Field quality (inexplicably) good • QT ran 13% above 140 T/m in 3 T background field at 4. 3°K and almost reached operating gradient at 4 and 5 T background at 4. 22°K. • By pulling a vacuum on the test dewar, we brought QT to 3°K & got similar result @ 6 T background. • Still from these data we expect that at 1. 9°K and 3 T background field Iq should be 1100 A (Iop = 664 A). 30 4 Apr 06
ILC Final Focus Magnet R&D - Short term goals Balance of FY 06: – Fabricate and test a short Octopole/Sextupole coil. Higher order magnetic elements require tighter bend radius onto a very small (20 mm) tube. This is proving to be non-trivial – Continue the 14 mrad design – Start to think about how to wind a 2 m coil 31 4 Apr 06
ILC Final Focus Vibration R&D • The basic issue: – The final focus magnet system is sensitive to vibration in the 10 -100 Hz range at the tens of nanometer scale. – Cryogenic magnets in addition to requiring external stabilization also can possess internal vibration modes which are potentially excited by cryogenic flow. • The R&D program needs to: – Directly measure mechanical coil vibration inside the cryostat – Make direct measurements of the field center stability • FY 06 plan is to develop measuring techniques that can potentially meet these criteria 32 4 Apr 06
ILC Final Focus Vibration R&D: Laser Set up for Horizontal Measurements • Use a RHIC style quadrupole assembly to commission a laser vibrometer and develop measuring techniques inside the cryostat No attempt to reduce vibration beyond shock mounts in a very noisy area (a large common mode signal) 33 4 Apr 06
ILC Final Focus Vibration R&D: Initial results We have demonstrated that we can measure cold mass motion at the required sensitivity in a cold environment in the presence of a large common mode signal. No large effect from cryogenic flow but a RHIC CQS element is (manifestly) not an ILC final focus magnet. 34 4 Apr 06
ILC Final Focus Vibration R&D: FY 06 • For the balance of FY 06 we intend to reduce the common mode signal on the measuring stand with actively stabilized tables for laser supports. • We are investigating the use of a magnetic probe for direct field measurements. We have “borrowed” a probe from CERN to this end. – It would be very nice to be able to correlate the mechanical and magnetic measurements • Starting to develop the concept for how to make these measurements on an ILC prototype magnet 35 4 Apr 06
ILC BDIR Energy Deposition Activities at Fermilab 3. 10. 6 • Nikolai Mokhov – group leader • A. Drozhdin, N. Mokhov, S. Striganov, X. Yang – all not full time. • M. Kostin moved to MSU -> N. Nakao will start on May 1 1. BDS Collimation System • Performance optimization • Aperture definition • Component survivability at normal operation and for misbehaved beam • Optimization of components wrt magnet protection, dynamic heat load, radiation damage, radioactivation, & environment impact • Magnetic muon spoilers in the tunnel 36 4 Apr 06
2. BDS & IP Source Terms for Backgrounds and Radiation Loads in BDIR and Extraction Beam Lines • STRUCT-MARS: 1. Particle spray from beam halo interactions with BDS collimators and magnets (muons are a major concern for backgrounds and human irradiation, but can be suppressed by tunnel spoilers) 2. Synchrotron photons from beam core and halo upstream IP (very intense, but suppressed with appropriate photon mask). • GUINEA-PIG: 1. Disrupted beam and its synchrotron photons: main source in general. 2. Incoherent e+e- pairs: important source. 3. Radiative Bhabhas: as important as (2). 4. Beamstrahlung photons: negligible for rad. loads. 5. Hadrons from gg interactions: negligible for rad. loads. 37 4 Apr 06
3. Beam Loss and Radiation Loads in IP and Extraction Line for 2, 14 and 20 -mrad Crossings • Detailed STRUCT modeling of beam loss and design of protection masks. • MARS calculations of radiation loads, heating, quench stability of SC magnets, radiation damage, radioactivation, shielding and impact on environment in detector, final doublet, extraction and incoming beamlines. 38 4 Apr 06
Radiation Loads in 20 -mrad Extraction Line • • 39 Dynamic heat loads up to 500 W/m Power density above quench limit Peak dose in coils up to 270 MGy/yr 2 -mrad x-ing: 0. 76 MW synch rad loss 4 Apr 06
4. BDS and IP Related Backgrounds in ILC Detectors • MARS 15 & GEANT 4/SLIC modeling of BDS + Si. D detector • Hit rates and occupancy in each sub-detector due to both BDS and IP • Tolerable limits for each subdetector, each sensitivity window (timing) with and without muon spoilers in the tunnel 40 4 Apr 06
5. Other BDS Radiation Physics Tasks at FNAL • Task list that Fermilab colleagues are working on – Earth thickness needed to shield IR 2 Hall where IR 1 tunnel passes by or vice versa. – Assuming detectors are not self-shielded, what concrete wall thickness in the Hall is needed to separate the assembly area or local counting house from the IP/detector area. – Detector self-shielding requirements for a single IR hall. – Shielding requirements for a single IR hall assuming detectors are not self-shielding. – Need for muon spoilers for PPS reasons or in general, PPS thoughts/designs related to 500 Ge. V beams heading down linac tunnel with/without 2 nd IR or push-pull. – Air activation and ground water shielding needed for the commissioning dump and the extracted beam dump, as well as photon dumps. – Tunnel wall and floor requirements for ground water activation in the betatron collimation section (also E-coll & possibly big bend), recommend local shielding if necessary. – For a shallow tunnel site, check the minimum depth for neutron and muon shielding. • Other tasks – Evaluation of crab cavity aperture and design of its mask (STRUCT). – MARS modeling of prompt and residual radiation fields around the vertical RF test facility and design of radiation shielding. – Planned study of a possible use of bent crystals for BDS collimation and beam manipulation before and after IP 41 4 Apr 06
Magnet Mover Design & Prototype, Status as of March 06 David Warner, Colorado State University 3. 10. 7 • Built a 3 degree of freedom (X, Y and Roll (Single about beam axis) kinematic magnet mover based on SLAC design • Replaced the standard 200 step per rotation stepper motors and mechanical 100: 1 harmonic drives with precision microstepper motors achieving >200, 000 steps per rotation (30 m. R/step). • The Micro-stepped mover is theoretically capable of motions <50 nm/step in X and Y. • Further plans include – Expand the prototype to allow control of 5 degrees of freedom (3 angles, X, Y) – Investigate Piezoelectric stack fine motion control and/or active feedback mechanisms to improve precision and stability of mover (if necessary 42 4 Apr 06
Initial test results • Measure position of the mounting plate of the mover using a capacitive sensor, with 10 nm resolution, as well as an encoder for measuring shaft rotation to 38 m. R precision. • Initial measurements moving one motor show a step resolution of 40 nm/step and drift of approximately 300 nm/10 hrs. Recent measurements show larger drift (~350 nm/15 min), the cause is being investigated 43 4 Apr 06
BDS R&D. Summary • BDS activity was presented to you in this talk – – – beam delivery system design ESA BDS/MDI Experiments BNL Final focus quadrupole Fermilab Beam delivery system-collimators Colorado Univ. Movers • In 2007 -9 plan for significant ramp-up to meet the TDR goals 44 4 Apr 06
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