Transcript Presentation

EUROTeV Diagnostics WP5
CAVBPM: Precision BPM.
WBCM: Wide band current monitor.
EUROTeV June 22 2005
Lars Søby, CERN AB
1
PBPM- deliverables
• Prototype PBPM:
• Design and build prototype.
• Report on bench tests:
• Design and build high resolution (100nm), mechanical
stable test bench.
• Develop front end electronics.
• Measure PBPM.
• Report on beam tests:
• Build 3 PBPMs with separate supports and test with
CTF3 beam.
EUROTeV June 22 2005
Lars Søby, CERN AB
2
PBPM-Requirements
EUROTeV 
ME 
•
•
•
•
Aperture:
Resolution:
Absolute precision:
Rise time:
Dynamic range:
Linearity error:
24H stability:
Vibrations
Low frequency cutoff:
High frequency cutoff:
Bake out temperature:
Operating temperature:
Vacuum:
EUROTeV June 22 2005
Lars Søby, CERN AB
4mm
100nm
10μm
<15ns
±1.5mm (15 bits)
< 1%
1μm
<100nm
100kHz
30MHz
150C
~20C
10-9 Torr
3
PBPM-beam parameters
ILC
CLIC
5Hz
150Hz
Beam pulse length
950μs
58ns
Bunch spacing
337ns
267ps
1ps
0.1ps
Charges per bunch
2E10
2.5E9
Nb of bunches
2820
220
3220A (0.3A)
4023A
9.5mA
1.5A
Repetition rate
Bunch length
Peak current (LP 30MHz)
Mean current per pulse
For CLIC the BPM’s are foreseen for the main Linac, with
minimum one BPM per quadrupole i.e. 2600 BPM’s.
We need additional BPM’s for the accelerating structures which
could bring the number up to 20000.
EUROTeV June 22 2005
Lars Søby, CERN AB
4
WCM as a BPM
R
f Low Sigma 
2    LBox
f Low Delta 
R
2    LElectrodes
 The image current distribution on the circumference reflects the
beam position.
 Intensity signal () = All resistor are voltages summed.
 Position dependent signal () = voltages from opposite resistors
are subtracted.
EUROTeV June 22 2005
Lars Søby, CERN AB
5
Inductive Pick-Up
RP 
RS
2n 2
 Electrodes are combined in pairs so that
each transformer sees half of the load
 Frequency low cut-offs are limited by
connection parasitic resistances and
primary electrode inductance.
Design: M. Gasior
EUROTeV June 22 2005
Lars Søby, CERN AB
6
Inductive Pick-Up
This is what we want to do!!
EUROTeV June 22 2005
Lars Søby, CERN AB
7
PBPM
•
•
•
•
Low sensitivity to beam spray, halo.
Independent on bunch spacing.
Low longitudinal impedance.
Low frequency FE electronics, could be
passive  cheap.
• Sensitivity OK.
• Complicated design.
• Mechanical stability in 100nm range?.
EUROTeV June 22 2005
Lars Søby, CERN AB
8
PBPM
Fellow hired from September 2005.
L. Søby working 5% in 2005 and 25% in 2006 and 2007
EUROTeV June 22 2005
Lars Søby, CERN AB
9
EUROTeV Diagnostics WP5
WBCM: Wide band current monitor.
EUROTeV June 22 2005
Lars Søby, CERN AB
10
WBCM- deliverables
• Report on BW limits:
• 3D EM simulations to identify high frequency
limits.
• Improved prototype system:
• Modify design and simulate.
• Build new WCM and test on bench.
• Report on beam tests:
• Tests with CTF3 beam
EUROTeV June 22 2005
Lars Søby, CERN AB
11
WBCM-Requirements
EUROTeV 
• Beam current monitor with > 20GHz
band width for measurement of
intensity and bunch to bunch
longitudinal position.
• Main beams, drive beams and
damping rings.
ME 
EUROTeV June 22 2005
Low frequency cutoff:
100kHz
Bake out temperature:
150C
Operating temperature:
20C
Vacuum:
10-9 Torr
100kHz-20GHz WB signal transmission
over 10-20m.
Lars Søby, CERN AB
12
WCM
Design: J. Durand, P. Odier
EUROTeV June 22 2005
Lars Søby, CERN AB
13
WCM
EUROTeV June 22 2005
Lars Søby, CERN AB
14
WCM
Impedance
Lf cut-off, direct output
250 kHz
Lf cut-off, integrator output
10 kHz
Hf cut-off
7 GHz
Number of feed thru
8
Gap length
2 mm
Beam aperture diameter
40 mm
Length
256 mm
Flange type
DN63CF
Max temp. bake-out
EUROTeV June 22 2005
4W
Lars Søby, CERN AB
150 ºC
15
WCM
EUROTeV June 22 2005
Lars Søby, CERN AB
16
WBCM
Scientific associate hired from January 2006.
L. Søby working 5% in 2005, 25% in 2006 and 2007
EUROTeV June 22 2005
Lars Søby, CERN AB
17
EUROTeV WP5
Thank you for your attention
EUROTeV June 22 2005
Lars Søby, CERN AB
18