a demonstration of high- gradient acceleration w. wuensch, c. achard… · 2003. 5. 5. · a...
TRANSCRIPT
A D
emon
stra
tion
of
High-
Grad
ient
Acc
eler
ation
W. W
uens
ch, C
. Ach
ard,
S. D
öber
t*, H
. H. B
raun
, I.
Syr
atch
ev, M
. Tab
orel
li, I
. Wils
on,
CERN
, Gen
eva,
Swi
tzer
land
ROA
A01
1, 1
5 M
ay 2
003,
PA
C 20
03
Acc
eler
atio
n in
CLI
C -
30 G
Hz,
150
MV/
m, 1
50 n
s 13
0 M
W, 2
0 J
Back
grou
nd,
Earl
y su
cces
ses
for
grad
ient
at
X-b
and,
150
ns
138
MV/
mPo
wer
limit
edA
t KE
K
153
MV/
mA
t SL
AC
But
spec
tacu
lar
failu
re a
t 30
GH
z, 1
5 ns
60 M
V/m
At
CERN
Prob
lem
s fo
r N
LC s
truc
ture
s to
o…
Is t
he d
iffe
renc
e fu
ndam
enta
l? Y
es.
Surf
ace
elec
tric
fie
ld e
nhan
cem
ent
in c
oupl
er
Som
ethi
ng*
rela
ted
to a
/l-
0.11
vs0.
2
Solu
tion
sto
cou
pler
fou
nd
But,
Lowe
r lim
it t
o a/l
-tr
ansv
erse
wak
efie
lds
* A
sub
ject
on
its
own…
Radi
cally
dif
fere
nt s
olut
ion
need
ed -
New
mat
eria
ls f
or h
igh
grad
ient
s
Tung
sten
, mol
ybde
num
, rho
dium
•Hig
h m
elti
ng p
oint
,•L
ow v
apor
pre
ssur
e •H
igh
elec
tric
al c
ondu
ctiv
ity
•Ple
nty
of h
igh
volt
age/
powe
r ap
plic
atio
ns
To:
Supp
ort
a hi
gher
sur
face
ele
ctri
c fi
eld
Surv
ive
the
effe
cts
of a
n rf
arc
(20
J re
mem
ber)
Firs
t te
st o
f ne
w m
ater
ials
in r
f st
ruct
ures
,En
d 20
01, i
n CT
FII
of W
cou
pler
iris
in c
oppe
r st
ruct
ure
gave
ver
y en
cour
agin
g re
sult
s –
•70
MV/
m, l
imit
ed b
y su
rrou
ndin
g co
pper
•c
oupl
er d
amag
e el
imin
ated
Copp
er a
nd T
ungs
ten
afte
r co
ndit
ioni
ng
Syst
emat
ic t
esti
ng o
f m
ater
ials
Test
a s
erie
s of
str
uctu
res
of s
tand
ardi
zed
desi
gn t
o co
mpa
re t
he r
elat
ive
perf
orm
ance
s of
Cu,
W a
nd M
o.
56 M
WPo
wer
for
E acc
eler
atin
g=15
0 M
V/m
2.2
E sur
face
/Eac
cele
rati
ng
8.3
nsFi
ll ti
me
4.6
%Gr
oup
velo
city
, vg/
c
3.5
mm
Beam
ape
rtur
e
2π/3
Phas
e ad
vanc
e
30+2
mat
chin
g ce
llsN
umbe
r of
cel
ls
29.9
85 G
Hz
Freq
uenc
y
Stan
dard
ized
30
cell
W, M
o an
d Cu
iris
str
uctu
res
Ass
embl
y by
bol
ting
Cu, W
and
Mo
Stan
dard
ized
tes
tsin
CTF
II w
ith
15 n
s pu
lses
Vacu
um c
an
mou
ntin
g fo
r fa
st
turn
-aro
und
Inst
alla
tion
in
CTFI
I
Cond
itio
ning
res
ults
00.
51
1.5
22.
53
x 10
6
050100
150
200
No.
of s
hots
Peak Accelerating field (MV/m)
3.5
mm
tung
sten
iris
3.5
mm
tung
sten
iris
afte
r ven
tilat
ion
3.5
mm
cop
per s
truc
ture
3.5
mm
mol
ybde
num
str
uctu
reC
LIC
goa
l loa
ded
CLI
C g
oal u
nloa
ded
00.
51
1.5
22.
53
x 10
6
050100
150
200
No.
of s
hots
Peak Accelerating field (MV/m)
3.5
mm
tung
sten
iris
3.5
mm
tung
sten
iris
afte
r ven
tilat
ion
3.5
mm
cop
per s
truc
ture
3.5
mm
mol
ybde
num
str
uctu
reC
LIC
goa
l loa
ded
CLI
C g
oal u
nloa
ded
Fiel
d le
vels
cal
ibra
ted
by a
ccel
erat
ed b
eam
!
Effe
ct o
n su
rfac
eCo
pper
260
MV/
mTu
ngst
en 3
40 M
V/m
Mol
ybde
num
426
MV/
m
Resu
lts
sum
mar
y (1
5 ns
)
426
MV
/m15
3 M
V/m
193
MV
/mM
olyb
denu
m
340
MV
/m12
5 M
V/m
150
MV
/mTu
ngst
en
260
MV
/m10
0 M
V/m
110
MV
/mC
oppe
r
Peak
surf
ace
Ave
rage
ac
cele
ratin
gPe
ak
acce
lera
ting
Stru
ctur
e
177
MV
/m
177
MV/
m a
vera
ge a
cceler
ation
grad
ient
at
30
GHz
with
8 n
s RF
pulse
s
228
MV/
m p
eak
acce
lera
tion
gra
dien
t
Puls
e le
ngth
dep
ende
nce
of C
u st
ruct
ure
510
1520
2530
350
100
200
300
400
500
RF-
puls
e le
ngth
(ns)
Maximum surface field (MV/m) 32 n
s po
int
mad
e us
ing
puls
e st
retc
her.
Dra
mat
ic im
prov
emen
t fr
om n
ew m
ater
ials
, m
any
new
ques
tion
s to
add
ress
,
A v
iew
to t
he f
utur
e.
Nex
t: W
and
Mo
scal
ed t
o X
-ban
d te
sts
at S
LAC,
30
GH
z, 2
00 n
s at
CTF
3