ATF2 Project at KEK. T. Tauchi, KEK at Orsay 17 June, 2005

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1 ATF2 Project at KEK T. Tauchi, KEK at Orsay 17 June, 2005

2 IP

3 Final Goal Ensure collisions between nanometer beams; i.e. luminosity for ILC experiment Reduction of Risk at ILC FACILITY construction, first result Optics Design beam size ATF2/KEK ? Pantaleo's local choromaticity correction scheme; very short and longer L* (β * y=100μm, Ltot=36.6m) 34nm / 2.2μm, aspect=65 (γεy=3 x 10-8 m) FFTB/SLAC Oide's conventional (separate) scheme; non-local and dedicated CCS at upstream; high symmetry; i.e. orthogonal tuning (β * y=100μm,, Ltot=185m) 60nm / 1.92μm, aspect=32 (γεy=2 x 10-6 m) Achieved? 70nm ( beam jitter remains!)

4 esign for the ATF2. A detailed report on comparison of these two.1: ATF2 proposed optics IP parameters in comparison with ILC. params ATF2 ILC Beam Energy [GeV] L [m] γ ɛ x [m-rad] 3e-6 1e-5 γ ɛ y [m-rad] 3e-8 4e-8 βx [mm] βy [mm] η (DDX) [rad] σ E [%] Chromaticity W y ~ L*/β*y

5 Mode-I A. Achievement of 37nm beam size A1) Demonstration of a new compact final focus system; proposed by P.Raimondi and A.Seryi in 2000, A2) Maintenance of the small beam size (several hours at the FFTB/SLAC) Mode-II B. Control of the beam position B1) Demonstration of beam orbit stabilization with nano-meter precision at IP. (The beam jitter at FFTB/SLAC was about 20nm.) B2) Establishment of beam jitter controlling technique at nano-meter level with ILC-like beam (2008 -?)

6 ATF2 Operation The mode-i and -II can not go together for BSM and IP-BPM at the same FP. First, ATF2 will operate in the mode-i with the BSM. Next, ATF2 will operate in the mode-ii with the IP-BPM. In long term, ATF2 will interchangeably operate the mode-i and -II.

7 Requirements Mode ATF-EXT ATF2 BSM (laser in higher mode) I Jitter < 30% of σy γε y =(4.5 3) x 10-8 m BPMs with 100nm res. at Qs Power supplies of < 10-5 Active mover of Final Q II Jitter < 5% of σy ( 2nm jitter at FP ) BPM with < 2nm res. at FP Intra-bunch feedback for ILC style beam

8 Mode-I

9 Optics; FF, diagnostic, ATF-EXT IP beam ATF-DR

10 betatron-spoilers for x-ing survivable with version ILC betatron-spoilers for x- survivable with version ILC ing IR SP2 IP phase SP3 SPE ABE AB10 AB9 AB7 IR ILCFF6.m N/ILC-like ATF2, Andrei FD phase Blue dashed- existing extraction line Red new final focus FF optics is NLC-like

11 10!1 Field strength error giving 2% effect on beam size ΔK/K ILC ATF Jitter position error giving 2% effect on beam size Δy_jitter ILC ATF2 10!2 (K, Ltot) 10 1 (σx σy) K/K 10!3 Y, micron !1 10!4 10!2 QM16 QM15 QM14 QM13 QM12 QD10 QD10 QF9 QF9 QD8 QF7 B5 QD6 QF5 QF5 QD4 QD4 B2 QD2B QF3 QD2A B1 QF1 QD0 10!3 QM16 QM15 QM14 QM13 QM12 QD10 QD10 QF9 SF6 QF9 QD8 QF7 QD6 QF5 SF5 QF5 QD4 SD4 QD4 QD2B QF3 QD2A SF1 QF1 SD0 QD Magnet tilt error giving 2% effect on beam size 10 3 Δtilt (σx/σy) ILC ATF Static position error giving 2% effect on beam size 10 2 Δy_static (σx σy) tilt, microradian QM16 QM15 QM14 QM13 QM12 QD10 QD10 QF9 QF9 QD8 QF7 B5 QD6 QF5 QF5 QD4 QD4 B2 QD2B QF3 QD2A B1 QF1 QD0 ILC ATF2 Y micron !1 QM16 QM15 QM14 QM13 QM12 QD10 QD10 QF9 SF6 QF9 QD8 QF7 QD6 QF5 SF5 QF5 QD4 SD4 QD4 QD2B QF3 QD2A SF1 QF1 SD0 QD0

12 coil will be removed to have the maximum sensitivity. The gain stability of the electronics is routinely monitored using a test signal generated by an external oscillator. coil Q-BPM The BPM s calibration will be done using the movers of the magnet on which it is attached rigidly. Beam FTM110=6.426GHz 20mm dia. beampipe L = 12mm Resolution = 100nm x-y isolation < -30dB based on the KEK cavity BPM. beam pipe Cav.BPM coil Q magnet Figure 1: Cavity BPM attached on a quadrupole magnet. sensor cavity Q magnet Cav.BPM coil Figure 1: Cavity BPM attached on a quadrupole magnet. sensor cavity beam pipe sensor cavity coax. cable coax. cable antenna antenna wave guide wave guide coupling slot coupling slot

13 KEK 3-Cavity BPM system for nm resolution study Goal < 2nm KEK Design nm mover and nm position feedback, KEK design BPM and electronics position (nm) nm rms 60 feedback on GHz cavity BPM. 00 cavity and are Sensor reference cavity in one body. time (sec) Symmetric signal extraction. Performance of nm Mover System is under beam test now 3 BPMs on nm mover, BPM Y positions are locked by laser interference position monitor and piezo actuator feedback.

14 KEK cavity BPM Y. Honda, 3rd mini-workshop of Nano project at ATF, 30-31, May,2005, KEK Resolution Result estimated resolution: 72 nm (with cut),116 nm (all data) electronics noise limit: 25 nm (estimated by disconnecting the sensor cavity)

15 BINP cavity BPM Preliminary Resolution! ~ 20 nm Individual BPM resolution is better, this is measurement prediction from 2 other BPMs Calibration scale is clearly off by ~20% Steve Smith - Dec 04 Author Name Date ATF2 Workshop Slide #

16 Mode-II

17 Novel IP-BPM R&D V. Vogel D 6 IP 250mm 450mm 5mm diameter beam pipe Asymmetric resonant cavity ATF2 FF BPM with 2 nm resolution (Y), frequency ~ 10 GHz, with damped Q for symmetrical for flat modes, beamand magic T inside BPM, design is under way now. FTM110=9GHz Leff=7mm Resolution = 1-2nm Angle sensitivity = 1nm/200μrad BPMs for FF composite of three cavity. 1. Reference phase, bunch length measurement, bunch angle/tilt. 2. For X position measurement. 3. For Y position measurement under the large beam divergence of 300μrad and the bunch length of 8mm 4. Loss part for damping high order modes in the beam tube

18 slot post Rv.t.=8mm Rv.t=6mm Rv.t=5mm beam pipe Figure 4: Electric field of the dipole mode in the IP-BPM. Angle signal (TE011) BPF to ADC reference cavity Charge signal (TM010) 6400 MHz 3890 MHz IP BPF to ADC CW local oscillator (synchronized to the beam) sensor cavity Distance along Z (mm) 9000 MHz mm Vacuum tube 6 mm Vacuum tube 8 mm Vacuum tube 4 mm MHz 9000 MHz RF switcher BPF discriminator BPF 8286 MHz BPF 1! 10 3 W_1 ( f1) Pout W_2 ( f1) 1" 10! limiting amp Bunch length signal (TM020) to ADC MHz BPF Y out -80dB isolation " f1 0!/2 phase adjust by post synchronous detector Frequency (GHz) In phase component to ADC Out phase component to ADC X out 10.1 " 10 9

19 Q=1*10^10, Zload=50 Ohm,!=1"10^-9 m, 3.78! 10 / Leff =7mm Dtube =5mm #z = 8 mm Thermal noise (df=3 MHz, T = 300K) 1.57 µv Qload=1500 $ = 2.0 BPM output voltage (V) Ts1 ( f) Ts2 ( f) BINP BPM! f Frequency (GHz) ) $ * Z * R load V = % *10.8*! * q * f *( Q) * T (' / 2)* S( (,# z )* +, - (1 + $ )*2* Qload. sin( ("# /2* ) 2 2 ( z ) z c 2 S (,# =,... S( (,# ) exp( * / 2* ) /2* z = ( # z c ("# c T( ' ) = % " Leff sin( ) & % " Leff & z 0.5

20 Amplitude of GM VerticalV M.Masuzawa, 2nd mini-workshop on nano project at ATF, 11 Dec.2004 R B D! ATF2 floor 40nm (beam spot size) 5 nm (beam size) 2nm at Final-Q (Δy*=4nm) ATF-EXT floor ~13Hz ~25Hz F N n Final-Q must be stabilized! Also, IP-BPM! Hz T

21 Cost Estimation Total 4.0+α Oku-yen labor for setup Shintake monitor CF:floor, shield etc. magnets laserwire power supplies Q-BPMs magnet supports including movers feedback control vacuum alignment

22 Optimal Design (1) mini-ilc model equal sharing on the components, while the host country prepares the conventional facility. (2) tentative status (1) Europe N.America Asia (host) a la Japanese costing rule not decided major components (1.14 Oku-yen) bend, 6,8poles power vacuum supplies (2) not decided Asia (host) Europe N.America

23 Floor Installation Inst Shield Magnets Instrumentation (BSM, BPMs, laserwire, feedback...) IP-BPM production test@atf test test@atf installation Power Supply Support Tables Jitter control: Feedforward from DR Jitter to EXT control: Feedforward from DR to EXT FONT5 of nm feedback system at KEK and SLAC/LLNL NanoBPMs FONT 6? Vacuum pipes, pump Alignment system Control system install ILC-kicker? Proposal Design Summer shutdown Summer shutdown C D R Summer shutdown 1st beam mode-i Summer shutdown mode -I mode-i Summer shutdown mode -II

24 Within the framework of the ILC-WG4 After LCWS05: Near final BDIR workshop, UK, June