PSI - East Altitude curves: 10 mhome.physics.ucla.edu/.../Talks/Kim_Electron_Beam_Gen.pdf3 500 m Altitude curves: 10 m 0 100 200 300 400 PSI - West SLS PSI - East Access road tunnel

Yujong Kim

PSI, CH-5232 Villigen PSI, Switzerland

[email protected], http://www.PSI.ch/~kim_y, http://FEL.WEB.PSI.ch PSI XFEL-2009-46

Stability Issues for the Coherent Single Spike

Mode Operation with Ultra-Low Charges

500 m

Altitude curves: 10 m

0 100 200 300 400

PSI - West

SLS

PSI - East

Access roadtunnel

linac

undulator hall+ beam dump

userarea

photontransport

250 MeV Injectortest area

Tunnel entry + Injector area

Aare

N

Workshop on X-ray Science at Femtosecond to Attosecond Frontier, UCLA, May 18, 2009

Electron Beam Generation and

2

Outline

Introduction to the PSI-XFEL Project

Site Limitation

Required Beam Parameters

Optimized Injector for Various Single Bunch Charges

Design Concepts & Summary of 13 Optimized Linac Layouts

Optimized Linac Layouts for Nominal Operations at 0.1 nm with 200 pC

Optimized Linac Layout for Single Spike Operation at 0.1 nm with 2 pC

Optimized Linac Layout for Single Spike Operation at 1 nm with 10 pC

RF Jitter Sensitivities and Tolerances for 10 pC Operation

Overall FEL Stability & Performance under RF Errors

300 Times S2E Simulation Results for 10 pC with required RF Jitter Tolerances

300 Times S2E Simulation Results for 2 pC with loose RF Jitter Tolerances

300 Times S2E Simulation Results for 2 pC with tighter RF Jitter Tolerances

Summary & Acknowledgements

Low Emittance Gun based PSI XFEL Project - Yujong Kim of Paul Scherrer Institut, Switzerland

33500 m

Altitude curves: 10 m

0 100 200 300 400

PSI - West

SLS

PSI - East

Access roadtunnel

linac

undulator hall+ beam dump

userarea

photontransport

250 MeV Injectortest area

Tunnel entry + Injector area

Aare

N

LEG Test Facility

PSI-XFEL Facility

2008-2011 : 250 MeV Injector Test Facility - Commissioning will be started in October, 2009

2011-2016 : RF Gun + Short Linac + Cryo (?) In-Vacuum Undulator based 5.8 GeV PSI-XFEL Facility

PSI-XFEL - Limited Site

Low Emittance Gun based PSI-XFEL Project - Yujong Kim of Paul Scherrer Institut, Switzerland

PSI - West

total available length < 950 m

total available length for linac < 540 m

no way, it should be compact !

4

PSI-XFEL - Required Beam Parameters


required or expected parametersnominal operation mode upgrade operation mode

long pulse short pulse ultra-short pulse

single bunch charge (pC) 200 10 10

required max core slice emittance (µm) 0.43 / 0.38 0.18 0.25

required max rms slice energy spread (keV) 350 / 250 250 1000

required min peak current at undulator (kA) 2.7 / 1.6 0.7 7

required min beam energy for 1 Å (GeV) 5.8 5.8 5.8

required max saturation length† (m) 50 50 50

expected max bunch compression factor 125 / 75 240 2400

expected max projected emittance (µm) 0.65 0.25 0.45

expected rms photon pulse length at 1 Å (fs) 12 2.1 0.3

expected number of photon at 1 Å (×109) 24 1 4

expected bandwidth (%) 0.031 0.025 0.050

†assumed undulator parameters: K = 1.2, λu = 15 mm, <β> = 15 m, length ~ 70 m

Parameters for the PSI-XFEL Project to generate XFEL Photon beams at 1 Å

Gsat

Gsat LEe

PLL 20ln

34

uGL 2~/

3/122

22

1

4

1

K

I

I

n

u

A

pk

)/exp( Go LzPP ]cm[]T[934.0,2

12

2

2 uou BK

K

higher ρ shorter LG

5555

PSI-XFEL - 250 MeV Injector Test Facility


CTF3 RF GUN

RF tested @ 100 MV/m - two weeks operation at CERN

power for 100 MV/m = 22 MW with 4.5 s RF pulse

power for 120 MV/m = 25 MW

RF frequency ~ 2998.5 MHz

cell = 2.5 cells (One TM02 + Two TM01)

Q0 = 16300

number of bunch in a train = 48

cathode wall angle = 20 degree

total length ~ 0.25 m

full cell length ~ 50 mm

designed charge ~ 2.33 nC for CTF3

bucking solenoid main solenoid

6666



Parameters 10 pC 100 pC 200 pC

laser diameter on cathode 400 µm 857 µm 1080 µm

laser pulse length (FWHM) 3.7 ps 7.9 ps 9.9 ps

peak current on cathode 3 A 14 A 22 A

thermal emittance on cathode 0.072 µm 0.155 µm 0.195 µm

core slice emittance before / after BC 0.078 µm / 0.078 µm 0.213 µm / 0.213 µm 0.320 µm / 0.330 µm

projected emittance before BC 0.095 µm 0.233 µm 0.350 µm

bunch length before BC (rms) 1.05 ps 2.23 ps 2.80 ps

bunch length after BC (rms) 33.2 fs 117.6 fs 193.3 fs

peak current after BC 104 A 285 A 352 A

x / y projected emittance after BC 0.104 µm / 0.096 µm 0.268 µm / 0.233 µm 0.379 µm / 0.350 µm

arrival error for stable seeding at ~ 160 nm ~ 5.5 fs ~ 19.6 fs ~ 32.2 fs

min beam size on OTRs in 3FODO (rms) ~ 14 µm ~ 35 µm ~ 55 µm

7777



Commissioning of 250 MeV Injector Test Facility will be started in October 2009

D. Dowell calculated

thermal emittance

line (0.5 μm/mm)

P. Emma, XFEL2008 Workshop, Courtesy of D. Dowell

PSI LEG

Measurement

0.61 µm/mm

LCLS Measured Core Slice Emittance

CTF3 Simulation

0.72 µm/mm

Euro. LCLS Simulation

0.91 µm/mm

8

PSI-XFEL - Used Thermal Emittance


LCLS Core Slice Emittance Measurements:Q = 20 pC, E ~ 135 MeV

Method = QM scan with LOLA

E = 135 MeV

Q = 20 pC

Ecathode ~ 115 MV/m

laser = 253 nm (= 4.899 eV)

ΔTlaser ~ 3.8 ps (FWHM)

Laser profile = pseudo-Gaussian shape

ζz ~ 1.3 ps

Ipeak ~ 5 A

)(0.5

eV,)V/m(107947.3 ~

beamroundaforσσ,3

σε

schottky0ave

5

schottky

2

schottky0

,th

hK

E

cm

hyx

e

yx

Kave = 0.4 eV was used for our

CTF3 RF gun based injector

optimizations !

Kave = 0.63 eV was used for our

European LCLS RF gun based

injector optimization !

2

e

ave,th

3

2σε

cm

Kyx

9

PSI-XFEL - Optimized Injector for 2 pC


CTF3 RF Gun may generate an ultra-low emittance < 0.06 µm for 2 pC !

1010



CTF3 RF Gun may generate an ultra-low emittance < 0.06 µm for 2 pC !

for 2 pC, slice & projected emittances ~ εth = 0.042 µm

εnsc contribution to εslice is ignorable !

εprojected = 0.054 µm εslice = 0.044 µm

INSB01-RAC INSB02-RACGUN

Projected Emittance along Injector Slice Emittance at 172 MeV

After considering targeting slice emittance (~ 0.18 µm) at the end of linac,

we chose thermal emittance ~ 0.072 µm & a low peak current of 3 A at the cathode.111111



CTF3 RF Gun may generate a low emittance < 0.1 µm for 10 pC !

ASTRA Simulation Results with Space Charge

Projected Emittance along Injector

121212



Q = 10 pC

E = 167.654 MeV, = 0.021%

x= 105 m, y= 105 m, z = 316 m

nx= 0.095 m, ny= 0.095 m

Ipeak ~ 3 A, n,core,slice ~ 0.078 m

Excellent Projected & Slice Emittance !

Excellent Uniformity in Current Profile !

Better Twiss Mismatching Parameter !

Excellent Slice Emittance !

And Wide Uniform Range !

Slice Emittance at 167 MeV

INSB01-RAC INSB02-RAC

Good Invariant Envelope Matching !

Emittance Damping in Booster Linac !

Mismatching Parameter ζ at 167 MeV

GUN

131313

PSI-XFEL - Summary of Optimized Injector


Final beam parameters are at the exit of the 2nd S-band structure (130 MeV - 172 MeV).

Gun max gradient = 100 MV/m, assumed Kave = 0.4 eV.

For only Q 2 pC, εprojected εslice εthermal

For a much higher Q, εprojected εslice εthermal due to the nonlinear space charge force.

We can get an excellent emittance with a lower charge for the single spike mode operation!

ASTRA Simulation Results : CTF3 RF Gun based Injector for various Charges

Q laser length (FWHM) Ipeak, cathode laser ζx,or y εthermal εslice/εprojected

200 pC 9.9 ps 22 A 270 µm 0.195 µm 0.320/0.350 µm

150 pC 9.0 ps 18 A 245 µm 0.177 µm 0.272/0.283 µm

100 pC 7.9 ps 14 A 214 µm 0.155 µm 0.220/0.233 µm

50 pC 6.2 ps 8.7 A 170 µm 0.123 µm 0.160/0.174 µm

20 pC 4.6 ps 4.7 A 125 µm 0.091 µm 0.108/0.122 µm

10 pC 3.7 ps 3.0 A 100 µm 0.072 µm 0.080/0.096 µm

5 pC 2.9 ps 1.9 A 79 µm 0.057 µm 0.062/0.074 µm

2 pC 2.1 ps 1.0 A 58 µm 0.042 µm 0.044/0.054 µm

14

PSI-XFEL - Linac Design Concepts


Generate high quality electron beams to keep the saturation length smaller

than 50 m for 1 Å.

Keep length of whole linac as short as possible due to a bridge at 544 m.

To minimize space charge effects and COTR, avoid a dog-leg or BC1 at a low

energy (BC1 @ ~ 450 MeV, no dog-leg, no strong beam waist before BC1).

To minimize CSR, keep somewhat high energy spreads at BCs for weak strength

chicanes but keep ζδ ≤ 1.7% @ BC1 ≤ 0.55% @ BC2 to avoid chromatic effects.

Module type diagnostic sections to measure beam parameters without change optics.

To reduce the bandwidth of XFEL photon beams, keep a small energy chirp and

energy spread at the end of linac as small as possible (C-band linac is promising!)

By choosing weak strength QMs and by keeping small beta-functions and somewhat

low phase advances in FODO cells, minimize chromatic effects in whole linac.

To avoid too tight RF jitter tolerances, choose the near on-crest RF phases and

smaller bunch length compression factors if possible.

For single spike mode with 2 pC and 10 pC, make a short bunch to satisfy:

z 2×cooperation length

1515Low Emittance Gun based PSI-XFEL Project - Yujong Kim of Paul Scherrer Institut, Switzerland

PSI-XFEL - Efforts on Chirp & Bandwidth

Optimization-V

chirp for Ipk = 2.7 kA

Optimization-III, VI, VII

chirp for Ipk = 1.6 kA

wavelength = 0.1 nm @ FEL1

no of photon per pulse ~ 1.0×1011

saturation length ~ 40 m with 2.7 kA

saturation length ~ 48 m with 1.6 kA

From our recent full S2E simulations with ASTRA, ELEGANT, and GENESIS codes

(Y. Kim and S. Reiche), we confirmed that we can effectively minimize the bandwidth

of XFEL photon beams by optimizing energy chirping of electron beams.

BW ~ 0.05% for Ipk = 1.6 kABW ~ 0.1% for Ipk = 2.7 kA

Optimization-III & V

S-band based Linacs

Linac Length = 650 m

Optimization-VI & VII

C-band based Linacs

Linac Length = 540 m, 510 mSaturation Length < 50 m !!!

1717

PSI-XFEL - Several Optimized Layouts


Optimization-III with a longer S-band RF Linacs for Chirp Compensation

ASTRA up to exit of SB02 & ELEGANT from exit of SB02 to consider space chare, CSR, ISR, and wakefields !

Optimization-I with S-band RF Linacs

1818Low Emittance Gun based PSI XFEL Project - Yujong Kim of Paul Scherrer Institut, Switzerland

Optimization-VI with S-band & C-band RF Linacs for Chirp Compensation


Optimization-V with S-band RF Linacs




Optimization-VIII with New Injector for 2 pC Single Spike Mode

New Injector Layout with Laser Heater & BC1 @ ~ 450 MeV


Optimization-VII with Shortest C-band RF Linacs for Chirp Compensation



Optimization-IX with X-band Linac for Chirp Compensation

Optimization-X with New Injector for 10 pC Nominal Mode





Optimization-XI with New Injector for 10 pC Single Spike Mode

single spike mode at 0.1 nm with 2 pC

rms bunch length ~ 0.43 fs @ 5.8 GeV

Optimization-VIII

photon

rms BW ~ 0.2%

rms pulse length ~ 140 as @ 0.1 nm

peak power ~ 19 GW

photons : 3.3e9

single spike mode at 1 nm with 10 pC

rms bunch lenght ~ 2.4 fs @ 3.4 GeV

Optimization-XI

photon

rms BW ~ 0.67%

rms pulse length ~ 280 as @ 1 nm

peak power ~ 10 GW

photons = 1.1e10

PSI-XFEL - Optimized Layouts

See details from Sven's talk later


10 pC - Investigation of Jitter Sensitivity

ASTRA & ELEGANT codes + Ming Xie Model were used to consider space charge,

CSR, ISR, short-range wakefield, and performance of XFEL.

We assumed that orbit feedback is running even though there are errors in linac.

By applying an artificial error set to single linac component and looking into FEL

performance from Ming Xie Model at the entrance of undulator, we checked

the impact of the error on FEL performance (sensitivity of the error).

To determine tolerances, we used FEL performance instead of linac performance.

S03 X01 BC1 LINAC1 BC2 LINAC2 3.4 GeV for 1 nm with 10 pC


10 pC - Criteria of Jitter Tolerance

To determine error tolerances for the single spike mode operation with 10 pC, at the

entrance of undulator (3.4 GeV), following FEL performance should be satisfied

when there is an error in a single machine component:

beam arrival time error Tarrival 5 fs (zero-to-max) ~ electron bunch length order.

saturation power error Psat/Psat 100% (zero-to-max) against any optics damage.

wavelength error / 0.01% (zero-to-max) against intensity lowering due to collimator.

saturation length error Lsat/Lsat 15% (zero-to-max) to get saturation with a given

undulator length (undulator length margin ~ 30-40%).

Please note that in rms (~ zero-to-max/3.0), they are about:

Tarrival 1.7 fs (rms), tighter than European XFEL (12 fs) due to a shorter bunch.

Psat/Psat 33% (rms), looser than European XFEL (5%)

/ 0.003% (rms), tighter than European XFEL (0.007%) due to smaller photons

Lsat/Lsat 5% (rms), looser than European XFEL (0.5%)


10 pC - Ultra-Sensitive Jitter Sources

FEL power change due to 10 X-band RF phase errors peak current fluctuation due to 10 X-band RF phase errors

error source : X-band (X01) RF phase

error range : -0.06 deg to +0.06 deg with10 steps

monitoring point : at the entrance of undulator @ 3.4 GeV

For Psat/Psat 100% (zero-to-max), X-band RF phase error 0.002 deg (rms)

This X-band RF phase tolerance is challenging !

X-band RF phase error, single bunch charge error, and injector S-band RF phase errors are

sensitive jitter sources to FEL saturation power.

wavelength ~ 1 nm

energy ~ 3.4 GeV

undulator period = 40 mm

beta-function ~ 10 m

K ~ 1.6



saturation length change due to 10 timing errors peak current fluctuation due to 10 timing errors

error source : gun & laser synchronization timing

error range : -50 fs to +50 fs with10 steps


For Lsat/Lsat 15% (zero-to-max), gun timing jitter 1 fs (rms).

This gun timing jitter tolerance is challenging !

wavelength ~ 1 nm

energy ~ 3.4 GeV



K ~ 1.6

gun timing error, X-band RF phase error, and injector S-band RF phase errors are sensitive

jitter sources to FEL saturation length.



arrival time change due to 10 S-band voltage errors arrival time fluctuation due to 10 S-band voltage errors

error source : RF voltage of S-band linac (S03) in injector

error range : -0.10% to +0.10% with10 steps


For Tarrival 5 fs (zero-to-max), S-band RF voltage error 0.005% (rms).

This S-band RF voltage tolerance is challenging !

~ 60 fs

BC1 chicane power supply error, gun timing error, injector S-band RF voltage and phase

errors are sensitive jitter sources to photon beam arrival time.



wavelength change due to 10 S-band phase errors long. phase space & peak current fluctuation due to errors

error source : RF phase of S-band linac (S03) in injector

error range : -0.06 deg to +0.06 deg with10 steps


For / 0.01% (zero-to-max), S-band RF phase error 0.005 deg (rms).

This S-band RF phase tolerance is challenging !

~ 30 fs

injector S-band RF phase errors and LINAC1 RF phase and voltage errors, and LINAC2 RF

phase and voltage errors are sensitive jitter sources to photon beam wavelength.

wavelength ~ 1 nm

energy ~ 3.4 GeV



K ~ 1.6

282828282828

10 pC - Summary of Tolerances


parameters tolerance (rms) tolerance source

gun laser arrival timing error ≤ 1 fs (rms) saturation length, arrival time

single bunch charge error ≤ 1% (rms) saturation power

injector S-band RF phase error ≤ 0.005 deg (rms) power, wavelength, arrival time

injector S-band RF voltage error ≤ 0.005% (rms) arrival time

injector X-band RF phase error ≤ 0.002 deg (rms) power, saturation length

injector X-band RF voltage error ≤ 0.011% (rms) arrival time

BC1 dipole power supply error ≤ 7.5 ppm (rms) arrival time

LINAC1 S-band RF phase error per klystron ≤ 0.015 deg (rms) wavelength, power

LINAC1 S-band RF voltage error per klystron ≤ 0.010% (rms) wavelength, arrival time

BC2 dipole power supply error ≤ 7.5 ppm (rms) arrival time

LINAC2 S-band RF phase error per klystron ≤ 0.017 deg (rms) wavelength

LINAC2 S-band RF voltage error per klystron ≤ 0.011% (rms) wavelength

These are tolerances for the single spike mode at 1 nm with 10 pC.

Tolerances of the single spike mode at 0.1 nm with 2 pC are much tighter than these things !

Tolerance Criteria for Single Component Error

Tarrival 1.7 fs (rms)

Psat/Psat 33% (rms)

/ 0.003% (rms)

Lsat/Lsat 5% (rms)

292929292929

10 pC - 300 Times S2E Simulation with Errors


gun timing error ≤ 1 fs (rms)

bunch charge error ≤ 1% (rms)

injector S-band RF phase error ≤ 0.005 deg (rms)

injector S-band RF voltage error ≤ 0.005% (rms)

injector X-band RF phase error ≤ 0.002 deg (rms)

injector X-band RF voltage error ≤ 0.011% (rms)

BC1 & BC2 dipole power supply error ≤ 7.5 ppm (rms)

LINAC1 S-band RF phase error per klystron ≤ 0.015 deg (rms)

LINAC1 S-band RF voltage error per klystron ≤ 0.010% (rms)



To see overall FEL Performance under various errors, we performed 300 times S2E

simulation with following random Gaussian errors (3 cut). Here, we considered all

collective effects such as space charge, CSR, ISR, and short-range wakefields.

Required Tolerances for 10 pC

303030303030



median : ~ 1.0 µs

rms variation : ~ 5.5 fs

median : ~ 83 GW (80% core slices)

rms variation : ~ 86%

still some fluctuation when we include

all errors together!

median : ~ 20 m

rms variation : ~ 4.5%

median : ~ 1 nm


313131313131



median : ~ 3.4 GeV


median : ~ 0.69 µm


median : ~ 0.109 µm


median : ~ 9.1e4

rms variaiton : ~ 2.1e-4%

323232323232




bunch charge error ≤ 0.5% (rms)










Note that tolerances above are better than current LCLS situation (phase ~ 0.04 deg, dV/V ~ 0.04%) in S-band.

For 0.1 nm with 2 pC, if tolerances is loose, operation becomes really unstable:

S03 X01 BC1 LINAC1 BC2 LINAC2 5.8 GeV for 0.1 nm with 2 pC

Loose Tolerances for 2 pC

3333333333

2 pC - Dancing Longitudinal Phase Space


very dynamic peak current & slice parameters!












For 0.1 nm with 2 pC, if tolerances is loose, operation becomes really unstable:

Loose Tolerances for 2 pC

under loose tolerances for 2 pC, we performed

300 times start-to-end simulations to see the

fluctuation of the longitudinal phase space at

the entrance of undulator.

beam chirp and position are very dynamically

dancing !

under this situation, peak current, beam

arrival time, and slice beam parameters are

also very dynamically dancing, which induce

unstable XFEL photon beams.~ 100 fs

3434343434343434



median : ~ 1.5 µs

rms variation : ~ 16 fs



with loose tolerances, power fluctuation

is very strong.

median : ~ 19 m


median : ~ 0.1 nm


poor performance with loose tolerances to generate single spike at 0.1 nm with 2 pC!

353535353535














For 0.1 nm with 2 pC, we need much more tighter tolerances for stable operation:

S03 X01 BC1 LINAC1 BC2 LINAC2 5.8 GeV for 0.1 nm with 2 pC

Ultra-Tight Tolerances for 2 pC

363636363636














For 0.1 nm with 2 pC, we need much more tighter tolerances for stable operation:

Ultra-Tight Tolerances for 2 pC

under tighter tolerances for 2 pC, we

performed 300 times start-to-end simulations

to see the fluctuation of the longitudinal phase

space at the entrance of undulator.

beam position dancing was reduced and chirp

dancing was dramatically damped.

under this situation, peak current and slice

parameters are almost constant. Therefore,

XFEL power becomes more stable. But there is

some small fluctuation in beam arrival time.~ 40 fs

37373737373737



median : ~ 1.5 µs

rms variation : ~ 4.5 fs



with tighter tolerances, fluctuation

is damped.

median : ~ 19 m


median : ~ 0.1 nm


great performance but ultra-tight tolerances! we will not use 2 pC to generate single spike !

year requirements compression factor operation conditions

2010 ϕs 0.1 deg (rms) 1 for injector gun

V/V 0.1% (rms) with 22 A, 200 pC

2011 ϕs 0.06 deg (rms) 16 for injector BC1

V/V 0.06% (rms) with 350 A, 200 pC

2012 ϕs 0.04 deg (rms) 75 for XFEL BC1+BC2

V/V 0.04% (rms) with 1.6 kA, 200 pC


V/V 0.02% (rms) with 2.7 kA, 200 pC


V/V 0.01% (rms) with 0.7 kA, 10 pC

after 2020 ϕs 0.005 deg (rms) 2400 for XFEL BC1+BC2

V/V 0.005% (rms) with 7 kA, 10 pC

These are requirements for S-band RF for about 1 minute. Requirements of X-band are four times of S-band.

383838383838

PSI-XFEL - RF Development Milestone


100 for LCLS 250 pC case

34 for LCLS 1 nC case

No

min

al

Op

era

tio

n M

od

esU

pg

rad

e M

od

e

3939

Summary


By performing the invariant envelope matching properly, slice and projected

emittances at the end of injector are very promising. They are smaller than 0.1 µm for

10 pC and smaller than 0.4 µm for 200 pC. Operations with 10 pC and 200 pC are

considered as the nominal modes, while the ultra-short mode with 10 pC will be

considered as an upgrade option.

By the help of the excellent emittance, we can use the low charge operation to generate

the coherent single spike at X-ray region.

We designed 13 different linac layouts with S-band and C-band RF linacs. Among

them, C-band based ones satisfy our design goal more easily (linac length < about 530

m, saturation of FEL power within a 50 m long undulator).

To minimize the bandwidth of XFEL photon beams, compensation of energy chirping

is a critical thing, which is normally difficult for us to compensate with a short S-band

linac.

To realize the stable single spike mode operation at 0.1 nm with 2 pC, it seems that we

need ultra-tight RF jitter tolerances. However, in case the other single spike mode at 1

nm with 10 pC, its required tolerances are somewhat looser. Therefore, we selected the

single spike mode at 1 nm with 10 pC as an upgrade mode.

4040

Summary & Acknowledgements


The single spike mode with a low charge has lots of advantages. But we need a high

resolution beam diagnostic system and ultra-tight RF tolerances to operate it stably.

If users does not care of arrival timing error and power fluctuation, the single spike

mode will be a great operation mode with a low charge.

Y. Kim sincerely give thank to many PSI colleagues (H. Braun, M. Pedrozzi, V. Schlott,

J.-Y. Raguin, T. Schilcher, and S. Reiche), Dr. Inagaki and Prof. Shintake of

RIKEN/SPring-8, Prof. Matsumoto of KEK, Dr. Miura of Mitsubishi Heavy

Industries, Dr. Yushiro of Toshiba, K. Floettmann of DESY, M. Borland of ANL, D.

Dowell, Y. Ding, J. Frisch, and P. Emma of SLAC for their encouragements, valuable

comments, useful information, and discussions for these works.

And many thanks to Rasmus for his presentation of this talk instead of me!

Documents

PSI - East Altitude curves: 10 mhome.physics.ucla.edu/.../Talks/Kim_Electron_Beam_Gen.pdf3 500 m Altitude curves: 10 m 0 100 200 300 400 PSI - West SLS PSI - East Access road tunnel