The International Linear Collider ILC Status and Dubna

The International Linear Collider (ILC) – Status and Dubna Siting Grigori Shirkov Dubna, July 26, 2006 Международный Линейный Коллайдер

Linear Collider – two main challenges • Energy – need to reach at least 500 Ge. V CM as a start • Luminosity – need to reach 10^34 level

Luminosity & Beam Size • frep * nb tends to be low in a linear collider • The beam-beam tune shift limit is much looser in a linear collider than a storage rings achieve luminosity with spot size and bunch charge – Small spots mean small emittances and small betas: sx = sqrt (bx ex)

Beam Parameters • Requirements: – High luminosity – set by physics needs – Low backgrounds (small IP effects) – Forced to high beam power and small vertical spots • Details of technology determine other limitations – Rf cavities and power sources 10 m. A beam current – Damping rings beam emittances and number of bunches – Bunch compressors IP bunch length – Cryogenic systems duty cycle – Extensive cost optimization is required to balance systems • Linear collider will push many technological and beam-physics limits – Need to have operational flexibility to overcome unexpected problems

ILC Parameters Parameter range established to allow for operational optimization

Schematic of the ILC e-(e+) source and delivery system Main Linac (ML) Damping Ring(s) Beam Delivery System (BDS) Ring(s) To Main Linac (RTML system) Beam Dump (BD)

1 st stage ILC : 500 Ge. V 2 nd stage ILC : 1 Te. V - extension of main linac - moving of SR and BC

ILC Gun Schematic View laser room-temperature accelerating sect. standard ILC SCRF modules Guns sub-harmonic bunchers + solenoids Laser requirements: pulse energy: > 5 u. J pulse length: ~ 2 ns # pulses/train: 2820 Intensity jitter: < 5 % (rms) pulse spacing: 337 ns rep. rate: 5 Hz wavelength: 750 -850 nm diagnostics section DC gun: 120 ke. V HV Photocathodes: Ga. As/Ga. As. P strained super-lattice Room temperature linac: Allows external focusing by solenoids Same as e+ capture linac

ILC Gun Beam Specifications • Polarized electrons are produced by injecting circularly polarized photons(sz=± 1) on NEA Ga. As cathode.

ILC Gun Multi Bunch Laser I. Will, H. Redlin, MBI Berlin ►OPCPA (Optical Parmetric Chirped Pulse Amplification) system generates trains with a wide range of pulse length, 150 fs. . 20 ps (FWHM) ►Pulse energy: Emicro = 50 ~ 100 u. J Etrain = up to 80 m. J ►Available wavelength: = 790 ~ 830 nm ►Pulse train: up to 0. 9 ms Output pulse train of the OPCPA

Damping Rings • Damping rings have more accelerator physics than the rest of the collider • Required to: 1. Damp beam emittances and incoming transients 2. Provide a stable platform for downstream systems 3. Have excellent availability ~99% (best of 3 rd generation SRS) • Mixed experience with SLC damping rings: – Referred to as the “The source of all Evil” – Collective instabilities; Dynamic aperture; Stability • Damping ring designs based on KEK ATF, 3 rd generation SRS, and high luminosity factories – Experimental results provide confidence in design

Issues in the Damping Rings • Emittance tuning and error correction – Orbit correction and component stabilization • Injection/extraction of individual bunches – Kicker rise/fall time – very large rings to store 3000 bunches • Dynamic aperture – Long wigglers needed if the ring is too big • Single-bunch intensity – Tune shift by self-Coulomb force (space charge) • Instabilities (mainly average current) – Electron cloud instability – Fast ion instability – Classical collective instabilities • Rings operate in a new regime with fast damping and very small beam emittances

An aside: the damping wiggler • The damping time in a storage ring depends on the rate of energy loss of the particles through synchrotron radiation. In the damping rings, the rate of energy loss can be enhanced by insertion of a long wiggler, consisting of short (~ 10 cm) sections of dipole field with alternating polarity. y z x The magnetic field in the wiggler can be approximated by: By = Bw sin(kzz)

Main Linac Design • Baseline Configuration Document (BCD) distilled from Snowmass Working Group recommendations in August 2005. • Major differences from 2001 Tesla TDR 500 Ge. V Design. – Higher gradient (31. 5 MV/m instead of 23. 4 MV/m) for cost savings. – Two tunnels (service and beam) instead of one for improved availability. • The Linac Area Group of the Global Design Effort (GDE) is continuing to evolve design.

Technical Challenges at the ILC Superconducting RF Acceleration technology - Nano-meter size beam handling technology Laser wire system

Acceleration 電場 Electric Field (陽)電子 Electron (positron)

Multi-cell Structures and Weakly Coupled Structures Cavities ● Field flatness vs. N Original Cornell N=5 High Gradient N =7 Low Loss N =7 TESLA SNS ß=0. 81 N=6 RIA ß=0. 47 N=6 RHIC N=9 SNS ß=0. 61 N=6 year 1982 2001 2002 1992 2000 2003 aff 1489 2592 3288 4091 3883 2924 5040 850 N=5 Field flatness factor For the TESLA cavities: field flatness is better than 95 %

1. 3 GHz TESLA Cavities ‣ Made with solid, pure niobium – it has the highest Critical Temperature (Tc = 9. 2 K) and Thermodynamic Critical Field (Bc ~ 1800 Gauss) of all metals. ‣ Nb sheets are deep-drawn to make cups, which are e-beam welded to form cavities. ‣ Cavity limited to ~ 9 cells (~ 1 m Long) to reduce trapped modes, input coupler power and sensitivity to frequency errors. ‣ Iris radius (a) of 35 mm chosen in tradeoff for low surface fields, low rf losses (~ a), large mode spacing (~ a 3 ), small wakes (~ a-3. 5 ).

Cryomodule with four 9 cell cavities 13 m

Cryomodule Design Relative to the TTF cryomodules – Continue with 8 cavities per cryomodule based on experience and minimal cost savings if number increased (12 in TDR). – Move quad / corrector / bpm package to center (from end) to improve stability. – Increase some of cryogenic pipe sizes (similar to that proposed for the XFEL). – Decrease cavity separation from 344 mm to 283 mm as proposed in the TDR.

Niobium: Electron Beam Melting • • High Purity Niobium(RRR>250) is made by multiple electron beam melting steps under good vacuum, resulting in elimination of volatile impurities There are several companies, which can produce RRR niobium in larger quantities: Wah Chang (USA), Cabot (USA), W. C. Heraeus (Germany), Tokyo Denkai(Japan), Ningxia (China), CBMM (Brasil) CBMM deposit in Araxa, Brasil EBM Ingots at CBMM EBM furnace at Tokyo Denkai

Fabrication(3)

Cavity Tests on Mono-cells - dedicated nozzle system for cavity cleaning developed [L. Lilje, CARE Meeting Nov. 2004, DESY]

Fabrication • Hydro forming (W. Singer, DESY) Spinning (V. Palmieri, INFN Legnaro)

Beam Delivery System challenges • Focus the beam to size of about 500 * 5 nm at IP • Provide acceptable detector backgrounds – collimate beam halo • Monitor the luminosity spectrum and polarization – diagnostics both upstream and downstream of IP is desired • Measure incoming beam properties to allow tuning of the machine • Keep the beams in collision & maintain small beam sizes – fast intra-train and slow inter-train feedback • Protect detector and beamline components against errant beams • Extract disrupted beams and safely transport to beam dumps • Minimize cost & ensure Conventional Facilities constructability

BDS: from end of linac to IP, to dumps BDS

Beam Delivery System • Requirements: – Focus beams down to very small spot sizes – Collect out-going disrupted beam and transport to the dump – Collimate the incoming beams to limit beam halo – Provide diagnostics and optimize the system and determine the luminosity spectrum for the detector – Switch between IPs

How to get Luminosity • To increase probability of direct e+e- collisions (luminosity) and birth of new particles, beam sizes at IP must be very small • E. g. , ILC beam sizes just before collision (500 Ge. V CM): 500 * 5 * 300000 nanometers (x y z) Vertical size is smallest 5 50 0 0 0 3

Modulators (115 k. V, 135 A, 1. 5 ms, 5 Hz) (~ 2 m Long) To generate pulse, an array of capacitors is slowly charged in parallel and then discharged in series using IGBT switches. Pulse Transformer Style Will test full prototype in 2006

Klystrons Baseline: 10 MW Multi-Beam Klystrons (MBKs) with ~ 65% Efficiency: Being Developed by Three Tube Companies in Collaboration with DESY Thales CPI Toshiba

Beam dump for 18 MW beam • • • Water vortex Window, 1 mm thin, ~30 cm diameter hemisphere Raster beam with dipole coils to avoid water boiling Deal with H, O, catalytic recombination etc.

The Big Picture: ILC Site Power ~ 330 MW Main Linacs 140 MW Sub-Systems 60 MW RF: 90 MW Injectors 78% Cryogenics: Damping rings 50 MW BDS Auxiliaries 65% 60% Beam 22 MW

Definitions ICFA - International Committee for Future Accelerators FALC - Funding Agencies for the Linear Collider ILCSC - International Linear Collider Steering Committee GDE - Global Design Effort RDB - Research and Development Board CCB - Change Control Board DCB - Design Cost Board CFS - Conventional Facilities and Siting BCD - Baseline Configuration Document RDR - Reference Design Report TDR - Technical Design Report WBS - Work Breakdown Structure International Organization

Global Design Effort

International Linear Collider Timeline 2005 2006 2007 2008 2009 2010 Global Design Effort Project Baseline configuration Reference Design Technical Design ILC R&D Program Expression of Interest to Host International Mgmt

THE 50 KM LINE

EUROPEAN SAMPLE SITE - CERN Longitudinal Section

EUROPEAN SAMPLE SITE - DESY Longitudinal Section

ASIAN SAMPLE SITE Longitudinal Section

AMERICAS SAMPLE SITE Longitudinal Section

ILC Tunnel Layout For baseline, developing deep underground (~100 m) layout with 4 -5 m diameter tunnels spaced by 5 m.

MAIN LINAC SERVICE TUNNEL VENTILATION Normal airflow for 1 mile per hour speed= 19, 000 cfm dry 100% outdoor air per tunnel = 0. 3 airchange per hour at 5 meter diamater tunnel. Airflow increase per CO 2 sensor. Smoke airflow (TBD) Assume 2 X = 38, 000 cfm (placeholder) ODH airflow (NONE). Service tunnel to be separated from Cryo cavern Construction Airflow (not included) Thermal load Airflow (Not included). Heat load to air will be handled by separate chilled water fancoils (see sketch) MAIN LINAC BEAM TUNNEL VENTILATION Normal airflow same as Service tunnel Smoke airflow (TBD) Assume 2 X = 38, 000 cfm ODH airflow (TBD). Construction Airflow (not included) Thermal load Airflow (Not included). Minimal load to air

OVERALL SCHEMATIC LAYOUT

EXTENT OF CONSTRUCTION • Main Accelerator Enclosures - 475, 000 m 3 • Main Accelerator Support Enclosures - 475, 000 m 3 • 2 Damping Ring Enclosures - 210, 000 m 3 • 12 Access Shafts - 70, 000 m 3 • Beam Delivery Enclosures - 160, 000 m 3 • 2 Interaction Halls - 800, 000 m 3 • Additional Support and Transport Enclosures - 300, 000 m 3 • Surface Facilities - 85, 000 m 2

Side View of Shielded Tunnel Boring Machine -W. Bialowans

Cutting Face of Modern Tunnel Boring Machines -W. Bialowans

Interaction Hall Schematics

Cryogenic Plants Water Processing Plants

Electrical Substations

ILC siting and conventional facilities in Dubna region

Joint Institute for Nuclear Research Dubna, Russia International Intergovernmental Organization 18 member states; 4 associate members

Advantages of Location - The international intergovernmental organization Joint Institute for Nuclear Research prototype of ILC host institution; - Experienced personal of JINR in accelerators, cryogenics, power supplies and etc. - Infrastructure and workshops of JINR on the first stage of ILC project realization; - The town Dubna provides with all the necessary means of transport to deliver all kinds of the equipment of the accelerator itself and its technological systems: highways, railways waterways (through Volga river to Black sea, Baltic sea, Polar ocean); - The international airport «Sheremetyevo» is situated at the distance of 100 km from Dubna (1. 5 hours by highway); - Developed Internet and satellite communication; - A Special Economic Zone (industrial+scientific) in the Dubna region (Edict of Russian Government, Dec. 2005), provides unique conditions in taxes and custom regulations; - A good position in the European region; - A positive reaction received in preliminary discussions with the interested governmental persons and organizations in Russia.

Russian Satellite Communications Center

Volga river 500 k. V power line 40 km Dubna city 30 km 20 km 10 km

Area and Climate The area is thinly populated, the path of the accelerator traverses 2 small settlements and a railway with light traffic between Taldom and Kimry. Possible “line” crosses only the railway to Savelovo (of low utilization) and the River Hotcha with a very small flow rate. The climate is temperate-continental. The mean temperature in January is – 10. 7 С. The mean temperature in July is +17. 8 С. The mean annual rainfall is 783 mm. The mean wind speed is 3. 2 m/s. Strong winds (15 m/s) blow only 8 days/year. According to the climatic parameters, the territory of Dubna is considered to be comfortable.

Power and energetics The northern part of Moscow region and the neighboring regions have a developed system of objects of generation and transmission of electrical energy. There are first-rate generating stations: the Konakovo EPS (electric power station, ~30 km from Dubna) and the Udomlia APP (atomic power plant, ~100 km from Dubna). Two trunk transmission lines with the voltage 220 k. V and 500 k. V pass through the territory of Dubna. The investigation of possibilities of the power supply for the accelerator and its infrastructure with the total power up to 300 MW gives the following variant: Construction of the power line-220 k. V, 35÷ 40 km long, directly from the center of generation – the Konakovo EPS to the Central Experimental Zone of the accelerator with a head step-down substations 220/110 k. V. It will require the investment in larger amount but the cost of power obtained directly from the centers of generation will be lower for 40÷ 50 % (from 0. 05$ per 1 k. Wh down to 0. 02 -0. 03 $ per 1 k. Wh in prices of 2006).

Relief The area of the proposed location of the accelerator is situated within the Upper Volga lowland. The characteristic feature of this territory is the uniformity, monolithic character of the surface. The existing rises of the relief in the form of single hills and ridges have smoothed shapes, soft outlines and small excesses. The territory of the area is waterlogged. The absolute marks of the surface range from 125 to 135 m with regard to the level of the Baltic Sea. The difference of surface marks is in the range of 10 m only on the base of 50 km.

Geology The area of the proposed location of the accelerator is situated within the Russian plate – a part of the Eastern European ancient platform – a stable, steady structural element of the earth’s crust. The Russian plate, like all the other plates, has a well-defined double-tier structure. The lower tier or structural floor is formed by the ancient – lower Proterozoic and Archaean strata of metamorphic and abyssal rocks, which are more than 1. 7 billion of years old. All these strata are welded into a single tough body – the foundation of the platform. The area of the ILC accelerator is located in the southern part of a very gently sloping saucer-shaped structure – the Moscovian syneclise. Alluvial deposits i. e. fine water-saturated sands, 1 -5 m of thickness. Below one can find semisolid drift clay of the Moscovian glaciation with exception of detritus and igneous rocks. The thickness of moraine deposits is 30 -40 m.

The ILC linear accelerator is proposed to be placed in the drift clay at the depth of 20 m (at the mark of 100. 00 m) with the idea that below the tunnel there should be impermeable soil preventing from the underlying groundwater inrush. It is possible to construct tunnels of the accelerating complex using tunnel shields with a simultaneous wall timbering by tubing or falsework concreting. Standard tunnel shields in the drift clay provide for daily speed of the drilling progress specified by the Project of the accelerator (it is needed for tunnel approximately 2. 5 y’s).

Documentation and Cost Estimation JINR prepared and filled the following Documents for the possible hosting ILC: BCD document (Conventional Facilities part) Site Assessment Matrix First official document from Russian State Project Institute with estimations on: Conventional facilities cost Siting (tunnel, land acquisition) cost and time schedule Energetics and power cost operational cost Labor cost The overall value on consolidated estimated calculations in the prices of year 2006 for civil engineering work, underground and surface objects of the main construction gives the sum in order of 2, 3 B$, including 1 B$ of costs of the tunnels construction for linear accelerator, all its technological systems and mines. Cost of power supply objects which will provide electric power directly from generator sources with special (favorable) cost of energy (tariff) is of order of 170 M$.

JINR participation in ILC Scientific Council of JINR (20. 01. 2006): • encourages JINR to be involved in the ILC design effort and to invest appropriate resources in scientific and technological developments to support its ability to play a leading role in the ILC project; • supports the intention of JINR to participate actively in the ILC project and the possible interest of JINR to host the ILC JINR Committee of Plenipotentiaries approved this recommendation on 25. 03. 2006 The Committee of Plenipotentiary Representatives of the Governments of the Member States is the supreme body governing the Institute. Structure Accelerator physics & techniques R&D Test facilities Infrastructure Siting Safety Detectors Detector concepts R&D Experiments &Tests Particle Physics Program for new physics & experiments

JINR at ILC Plans on opening of new theme JINR participation in design, construction and testing of prototype elements of the ILC accelerator complex (2007 -2009). Studying problem and main goal of researches: Development and creation of accelerator complex elements, study of the beam dynamics in linear colliders. Participating countries and international organizations Belarus, Germany, Italy, Russia, USA, Japan, CERN

1. Creation of the ILC injection complex prototype. Development and study of electron sources on the base of photocathode and control laser system. Creation and launching of the electron injector prototype with RF or DC gun. 2. Development and creation of the test facility on base of the electron linear accelerator LINAK-800 for testing with high-energy electron beam of accelerating RF resonators, beam parameter diagnostics and transportation channels prototypes for ILC. Creation of the free electron laser on the base of photo-injector and linac LINAK-800. Development and testing of RF system elements of the linear accelerator. 3. Researches on possible creation of high-precise metrological laser complex with extended coordinate length up to 20 km. 4. Development and creation of cryogenic modules for the acceleration system of linac. Participation in creation of design documentation (work drawings) in ANSYS standard for manufacturing at ZANON (Milano) plant the first cryostat prototypes for ILC.

5. Preparation of design documentation on creation of hardware-software complex and facility for study of cryomodules, with the goal of further transition to production of documentation for mass cryostats fabrication and/or their element with refering to technologies and standard group of of the work performers. 6. Theoretical study of electron beam dynamics in transportation channels using software packages, calculation of electric and magnetic fields in accelerating structures, transportation systems and systems of e-/e+ beam formation. 7. Preparation of the project of hardware-software complex for studies of radiation stability of superconductive materials using powerful , e, n beams 8. Engineering studies and design works with purpose of the study and preparing the possible hosting of ILC in the region near Dubna. 9. Development of the magnetic systems of ILC. Calculation on choosing parameters of electromagnetic elements for Damping Rings (DR). Development and creation of the magnetic systems on base of superconducting and warm electromagnets, also for constant magnet variant.

LHE ground Machinery Hall # 2: Possible place for location of the Test Bench for experiments on superconducting RF cavities. Adv: Large hall, Power supply, Water supply, very close to systems for liquid Helium and other cryogenics

LNP ground Building 118 Location of constructed LINAC-800. Test of RF accelerator sections and cryo modules LINAC with superconducting RF cavity (power, water, . . . LINAC-800 – first electron beam on 27. 04. 2006

LNP ground Building 108 (LEPTA project) 2 experimental Halls (water, power, …) Test Bench for Photo Injector

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