Beam injection and kicker KEK H. Iinuma and H. Nakayama I’ll talk about this part We measure Muon precession  1000  1 mission (a)Smooth injection without error field in the storage volume (b)Storage orbit’s plane should be stable <0.01mrad (c)Beam at storage volume ~few 10  m-rad TODAY 2014/11/71 (Assuming EDM ~ 1e-19 e.cm)

Image of beam injection into the storage volume 2014/11/72 Upper plate (pure iron) Return yoke (pure iron, cylindrical shape) Pole tip (pure iron) Main coil  + beam ¼ model (OPERA) From LINAC & transport line Super conductive solenoid magnet Main field 3 T 3m in height Outer radius of iron yoke; 2m Tunnel Today’s main topic: Stop the vertical motion by the kicker to storage into the weak focusing field Injection volume: Review briefly in the next page. Details are shown in slide from CM8 See slides from CM8 I also talk about the status of preparation of the e-gun test beam line, too!

Tunnel region y=110cm y~35cm 3~4 turns Stop vertical motion by the Kicker and storage into the weak focus field 3 y=82cm ~0 [T] 0.14 [T] Star mark ： Exit of tunnel ByBy BRBR 2014/11/7 Review trajectories in the injection volume

2014/11/7 Target :n=1.5E-4 n>0 :focus vertically (solenoid axis) n<1: focus radially we apply weak focus 4 rr y y ByBy BRBR Focus both direction at a time!! Simple harmonic motion ideal 4

Simple harmonic motion in the design field Abe-san tool FLDATA txt Simulate particle motion with RK4 Field at particle position is calculated from surface current distribution no grid field, that is, smooth field!!  0.3mrad 3  E-6[rad-m]  10mm Simple harmonic motion volume Kick!! 2014/11/75 Zoom up

Required kicker field 6 Id#  (ns) T(ns)B peak (gauss) 1(sin) (sin)∞ (half) (half)∞4803 5(half)∞ Pulsed axisymmetrically-excited field I am trying 5 types of sin and half-sin shapes. This study does not include spatial distribution B peak (=const.). Zoom up possible 2014/11/7

More typ#2 (sine shape) 2014/11/77  0.3mrad  10mm A)In case we use typ#2 kicker, vertical size of storage beam is ~ 3  E-6[m-rad]. B)As long as the weak focus field is stable, storage orbit’s plane should also be stable. C)Envelope of required vertical beam shape, at the kick point (y~35cm), is shown. D)I have confirmed “inverse trajectories” from y~35cm went out through tunnel.

Storage orbit’s plane 2-D orbit 8 Kicker (review) 2014/11/7 Pulsed current Pulsed Radial field ; B kick (t)=B peak  sin(  t)  exp(-t/  )  =  /T kick T kick ~500nsec Peak field B 0 ~2 gauss 2pairs of coil, pulsed high current I(t)=I peak  sin(  t) I peak  100A/coil B kick (t) axisymmetrically-excited field Vertical Kick

Spatial field distribution: design vs. measurement Solenoid and radial axes 2014/11/7 Measure pulsed field by pickup coil Uncertainty for each point is from reading fluctuation of oscilloscope mV 1 Gauss 2 Gauss y 2012/8/3 Signal from pickup coil (differential amplifier+ integrator) Current transfer Inner and outer coils 300nsec High current supply I(t)=I peak  sin(  t) I peak  100A/coil 9 (Review)

~190 ㎝ image Status report of the test beam line LINAC Mini solenoid magnet E-gun Grant-in-aid KIBAN-B momentum 112KeV/c Beam line height 90cm from the floor Beam line length 2m Height of top of solenoid magnet ~190cm 2014/11/710

新規製作 の架台 Example shot in Argon gas. Parameter comparison Strong points! 1.1/3 scale but, we install weak focus and kicker system 2.We fill Argon gas in the storage chamber. We can directly see the beam trajectory! 3.Electrons circulate inside storage volume forever!! 2014/11/711

Magnet Collimator inside camera By the end of FY keV e - Fluorescent plate Faraday cup By the end of FY2014 Vacuum check for the e-gun and chambers are done. HV-check of e-gun is now ongoing. We will have the first beam in the next week!!! 2014/11/712

Status of the electron-gun preparation 2014/11/713 Vacuum check is done, HV check including interlock is almost done,  Need some works for cathode,  We will have the first beam very soon! 110kV

Status at vacuum 2014/11/714 home made coil winder coil pole Vacuum check is done, Coil wind work for bend magnet is ongoing,  Vacuum system will move to the beam line on the next Monday.  And then, connect with the electron-gun.

3-D injection BOYS 2014/11/715

Summary and next 2016 Kicker install start studying of storage the beam 2017 Optimize the efficiency 2014 beam line preparation warm-up the e-gun fabricate the mini-solenoid magnet 2015 Injection commissioning Shall we do it now? I.Goal of Injection and kicker Beam phase space ~ several× E-6 [rad-m] at the storage volume Storage orbit’s plane should be stable <0.01[mrad] (Achieve sensitivity of EDM 100 times better!) II.Design of the weak focus field and kicker field are shown Kicker typ#2 can be possible candidate (B peak ~2 gauss) Possible vertical beam size at the storage volume is ~3  E-6[m-rad] (ref: beam size at the exit of LINAC is 1.5  E-6 [rad-m] ) III.Status report of the test beam line We will have the first beam in the next week! IV.NEXT Spatial distribution should be included in the kicker simulation Go through entire simulation from the beam transport line to the storage volume Outline of test experiment 2014/11/716

backups 2014/11/717

Basic concept of 3D spiral Injection BRBR Main soleno id coil Solenoid-axis (Z-axis) Main solenoid coil BZ: Solenoid axis component BR: radial component Z Decide injection angle  as a function of solenoid-axis; Z  Design specific magnetic field along the trajectory.  ?  beam  Radial field B R deflects beam direction and changes  Utilize fringe field Solenoid field  axial symmetry, Inject beam from upward Utilize fringe field, Storage beam in center region of solenoid field. Motion in the magnetic field ： Momentum is constant 2014/11/718

LINAC EXIT Beam from LINC: 1.5  E-6 [rad-m]  =0,  =10 Monitor install? free space 28cm Bend 12.5  Storage magnet 8.8m Not just a transport line. But we need to apply a proper X-Y coupling to beam. We need several skew quadruple magnets. In this design, we use 8 (small) skews. Transport line from LINAC EXIT to storage magnet Ver. 2014May Apply X-Y couplingFree drift LD=350cm Bend beam and control dispersion zero Free drift LD=350cm 2014/11/719

Transfer MATRIX of Transport line M M is transfer matrix of between point 1 and 2 D is Sectional Diagonal matrix (?) A and B are 2×2 Matrices U 1 and U 2 are rotation matrix at point 1 and 2 (4×4 Matrix) 0 A 1 2 2×2 matrix A and B are related to twiss parameters  1 and  1 are given value from LINAC Rotation matrix Eight FREE parameters:  2,  2 (for x and y components), R 1 ~R /11/7

 0.3mrad  0.3cm  =  E-6[m-rad]  =0,  =10 2K samples Transfer matrix Injection point y=150cm 21 LINAC EXIT Tunnel Entrance Red lines show X-Y coupling, x-x’ and y-y’ correlations x-x’ y-y’ x-y x’-y’ 1cm x-x’ y-y’ x-y x’-y’ 10mrad M NO X-Y correlation X-Y correlation /11/7

Rough estimation of acceptable error field 2014/11/722 Kick point 2 nd rotation 1 st rotation Orbit base plane 1 st turn 2 nd turn 3 rd turn m th turn Cross- section view If we request  y <2cm for 100 turns, If we request  x <5mm for 7000 turns