Transcript Accelerator R&D for Future Linear Colliders at IFIC Scientific Staff: Technical Staff:

Accelerator R&D for Future
Linear Colliders at IFIC
Scientific Staff:
A. Faus-Golfe, C. Alabau, J.J. García,
S. Verdu, J. Alabau
Technical Staff:
J.V. Civera, C. Blanch
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Capabilities
BEAM INSTRUMENTATION :
BEAM DYNAMICS EXPERTISE:
Optics design
- CALCULATION
Electromagnetic analysis
• Electric circuits & electronics
Mechanical analysis
Non-linear dynamics studies
New instrumentation techniques
Commissioning
- PROTOTYPING
Design: tooling, drawings
Fabrication follow-up
Assembly
Testing
3-D modelling ot BPM
Optics study for LHC non-linear collimation sysytem
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Main ongoing projects
ATF-ATF2:
Beam dynamic studies and commissioning of the EXT line (LAL, KEK, SLAC)
Instrumentation: New Multi-OTR system (SLAC, KEK)
BPM supports with micromovers for FONT4 (KEK, JAI)
CLIC-CTF3: BPM’s for TBL (UPC, CERN)
Pieces of BPM-TBL for CTF3
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Main Ongoing Projects:
ATF and ATF2: Emittance growth studies
ATF was built in KEK (Japan) to create small emittance beams.
The Damping Ring of ATF has a world record of the normalized emittance
of 3x10-8 m rad at 1.3 GeV.
ATF2 is being built to study the feasibility of focusing the beam into a
nanometer spot (~37 nm) in a future linear collider.
Extraction line
drives the beam
from ATF to ATF2
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ATF and ATF2: the Extraction Line
diagnostic section
extraction
wire scanners
(OTR)
OTR monitor
The beam passes horizontally off-axis
through the shared magnets with the DR
Since several years, the vertical emittane measured in the
diagnostic section of the EXT line is significantly larger
than the emittance measured in the DR.
Hypothesis:
Non-linear magnetic fields while passing off-axis
through the shared magnets
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ATF and ATF2: Non-linear magnetic fields
Computation of the non-linear magnetic fields of the magnets involved in the extraction
with the code PRIAM
BS1X septum magnet
QM7R
quadrupole
At the extraction (x=2.25 cm):
Extracted beam
Dipole component
appears
Polynomial fit of
the magnetic field:
Multipole coefficients:
Quadrupole
component reduced
~ 24% with respect
to the DR
Non negligible
sextupole
component
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ATF and ATF2: Tracking simulations including non-linear
fields in different magnets of the extraction
The non-linearity would have negligible
effect if the beam were always centerd
vertically, but increases when passing
vertically off-axis through QM7R.
The magnitude of the growth also
depends on the horizontal displacement,
increasing or decreasing in the outer and
inner parts of the magnet.
offset in QM7
Experimental Proposal
open the bump
in DR and EXT
Closed orbit bumps in the DR are used to
deviate the extraction trajectory and study
its correlation with the emittance growth
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close the bump in the DR
OTR monitor
ATF and ATF2: Experimental Work (Dec’07-May’08)
Measurements + simulatios for different horizontal extraction positions:
Beam size at the OTR/XSR (19th Dec’07)
Beam size at the OTR/XSR (28th May’08)
Measurements during different shifts:
- The results show an emittance growth with a strong
dependence with the extraction position.
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- But still there must be another source for the emittance
growth since in three of the data sets the extracted beam
was significantly larger than expected. It could be doe to
an anomalous dispersion, a large horizontal
displacement or to another mechanism.
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ATF and ATF2: Conclusions
Simulations including the non-linear fields in the extraction region predict a
significant vertical emittance growth while passing throug QM7R vertically off-axis.
The magnitude of the growth depends on the horizontal displacement, since the
non-linearity decreases going towards the center of the magnet.
Measurements using closed orbit bumps in the DR to probe the relation between
the extraction trajectory and the emittance growth were done:
- The results show an emittance growth with a strong dependence with the
extraction position.
- But still there must be another source for the emittance growth since the
extracted beam was significantly larger than expected in three of the data sets.
Recently, the QM7R magnet was replaced by a similar one with larger aperture, for
which magnetic measurements and simulations indicate that non-linear fields are
negligible at the extraction position.
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Main Ongoing Projects:
ATF and ATF2: New Multi-OTR System
diagnostic section
wire scanners
extraction
(OTR)
OTR monitor
Emittance measurements with the wire scanners located in the diagnostic section
of the EXT line are very slow.
Proposal:
multi OTR (4 units) (in collaboration with KEK, SLAC):
beam dynamics studies, design, construction, and characterization
including associated electronics
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OTR4
OTR3
OTR0
OTR1
OTR2
extraction
OTR1X
ATF and ATF2: New Multi-OTR System
diagnostic section
The location of the OTR’s has to be optimized such that the phase advances be
apropiate to allow emittance measurements
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ATF and ATF2: New Multi-OTR System
New design of the OTR
for ATF-ATF2
Current OTR installed in the ATF EXT line
CCD camera
target
New OTRs will have same controls and motion capabilities as current OTR
with the following improvements:
- Target actuator relocated to the top (no interference with the girder) and smaller
design  greater flexibility in the OTR placement
- Thinner target  reduce radiation damage
- CCD camera parallel to the target (before it was not parallel, which meant that the
beam spot was in focus on only a small portion of the target)  greater depth of field.
- 12 bit camera for more dynamic range with smaller pixel size for more resolution.
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Main Ongoing Projects:
ATF and ATF2: BPM’s supports with micromovers for FONT4
IP intra-train feedback system
•
•
•
Last line of defence
against relative beam
misalignment
Measure vertical position
of outgoing beam and
hence beam-beam kick
angle
Use fast amplifier and
kicker to correct vertical
position of beam incoming
to IR
FONT – Feedback On Nanosecond Timescales
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ATF and ATF2: BPM’s supports with micromovers for FONT4
Proposal:
BPM’s supports with micromovers for FONT4 (in collaboration with KEK, JAI)
design, construction, and characterization including associated electronics
Realignment of BPM to
increase the resolution
Range: ±1 mm
Step size: 10 μm
Stability better than 1 μm
Time response ~ sec
Planning:
1st prototype for Dec’09 (ATF2
shutdown)
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Main Ongoing Projects:
CLIC-CTF3: BPM’s for the Test Beam Line
16 Beam Position Monitors for the TBL (in collaboration with UPC, CERN):
designed, constructed, characterized and tested including supports and
associated electronics
The TBL is designed to study and validate the drive beam
stability during deceleration in CTF3. The TBL consists of a
series of FODO lattice cells and a diagnostic section at the
beginning and end of the line. Each cell is comprised of a
quadrupole, a BPM (labeled as BPS) and a Power Extraction
and Transfer Structure (PETS) .
3D View of aTBL cell
with the PETS tanks,
the BPS’s and the
quadrupoles
BPS Prototype
Inductive Pick-up (IPU)
TBL beam time structure
2.25 cm
Inductive
sensors PCB
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CTF3: BPM’s for the Test Beam Line
BPS Prototypes
A set of two prototypes of the BPS's labeled as BPS1 and BPS2
with its associated electronics has been designed, constructed
and characterized by the IFIC team with the collaboration of the
CTF3 team at CERN.
The characterization has been made with the wire method in the BIPI labs at CERN. This test is based on a test bench setup that
allows moving the BPS with respect to a current wire that
simulates the beam passing trough the BPS under test.
From the point of view of the electronics two different versions of
the PCB's, differing in the secondary output resistors used for the
adjustment of the low-frequency cut-off, has been also tested.
BPS1 Prototype Performance
BPS1 Sensitivity and Linearity Parameters
V Sensitivity, SV
41.09 m-1
H Sensitivity, SH
41.43 m-1
V Electric Offset, EOSV
0.03 mm
H Electric Offset, EOSH
0.15 mm
V overall precision (accuracy), σV (+/- 5 mm)
78 μm
H overall precision (accuracy), σH (+/- 5 mm)
109 μm
BPS1 Characteristic Output Levels
Sum signal level, Σ
16.5 V
Diff signals levels, ||ΔV||max, ||ΔH||max
8.25 V
Centered beam level, Vsec (xV = 0, xH = 0)
4.125 V
BPS1 Frequency Response (Bandwidth) Parameters
Σ low cut-off frequency, flΣ
1.76 KHz
Δ low cut-off frequency, flΔ
282 KHz
Σ[Cal] low cut-off frequency, flΣ [Cal]
1.76 KHz
Δ[Cal] low cut-off frequency, flΔ [Cal]
180 KHz
High cut-off frequency, fh
> 100 MHz
High cut-off frequency [Cal] fh[Cal]
> 100 MHz
BPS1 Pulse-Time Response Parameters
Σ droop time const, τdroopΣ
90 μs
Δ droop time const, τdroopΔ
564 ns
Σ[Cal] droop time const, τdroopΣ [Cal]
90 μs
Δ[Cal] droop time const, τdroopΔ [Cal]
884 μs
Rise time const, τrise
< 1.6 ns
Rise time const [Cal], τrise [Cal]
< 1.6 ns
The BPS1 and its support is already installed in the
TBL line. After the installation in March 2009 some
preliminary test with beam has been performed.
BPS1 and its support installed in
the TBL line
Measurements of the BPS1 with
beam in the TBL line
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CTF3: BPM’s for the Test Beam Line
BPS series production and characterization
The series production of the 15 unit (BPS1 + 15) have been started at the IFIC labs in November 2008.
We have characterized two units: a refurbished version of the BPS2 (PCB final version) and a new unit
labeled as BPS3.
DAQ equipment for all the
setup signals and
micromovers controller
The main features of this new
test bench setup is that the
BPS under test is moved by a
motorized XY and rotatory
micromovers to change the
relative wire position with
respect to the wire, and,
moreover, the wire is fed with a
higher current (>250 mA) to
avoid the low current effects in
the test measurements.
BPS2 and BP3 Series Performance
Sensitivity and Linearity Parameters
V Sensitivity, SV
H Sensitivity, SH
V Electric Offset, EOSV
H Electric Offset, EOSH
V overall precision (accuracy), σV (+/- 5 mm)
H overall precision (accuracy), σH (+/- 5 mm)
Low-frequency
wire set up at
the IFIC labs
3D view of the
Low-frequency wire
set up
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Characteristic Output Levels
Sum signal level, Σ
Diff signals levels, ||ΔV||max, ||ΔH||max
Centered beam level, Vsec (xV = 0, xH = 0)
Frequency Response (Bandwidth)
Parameters
Σ low cut-off frequency, flΣ
Δ low cut-off frequency, flΔ
Σ[Cal] low cut-off frequency, flΣ [Cal]
Δ[Cal] low cut-off frequency, flΔ [Cal]
High cut-off frequency, fh
High cut-off frequency [Cal] fh[Cal]
Pulse-Time Response Parameters
Σ droop time const, τdroopΣ
Δ droop time const, τdroopΔ
Σ[Cal] droop time const, τdroopΣ [Cal]
Δ[Cal] droop time const, τdroopΔ [Cal]
Rise time const, τrise
Rise time const [Cal], τrise [Cal]
BPS2
43.16 m-1
44.60 m-1
-0.67 mm
0.50 mm
89 μm
90 μm
BPS3
43.70 m-1
42.10 m-1
-0.84 mm
0.52 mm
94 μm
98 μm
16.5 V
8.25 V
4.125 V
16.5 V
8.25 V
4.125 V
2.90 KHz
1.70 KHz
271 KHz
275 KHz
2.80 KHz
1.70 KHz
163 KHz
171 KHz
> 100 MHz > 100 MHz
> 100 MHz > 100 MHz
55 μs
587 ns
57 μs
976 μs
< 1.6 ns
< 1.6 ns
17
93 μs
579 ns
93 μs
931 μs
< 1.6 ns
< 1.6 ns
CTF3: Conclusions
The series production of 15 units has already started. The production of the
different parts is finished.
One unit of the series: BPS3 was assembled. After the characterization test
made at IFIC labs in a new wire low-frequency setup, it was shipped to CERN
jointly with BPS2 and its corresponding supports.
These two units are being installed in the TBL line. The rest of the series will be
installed in July 2009.
Furthermore a high frequency setup for measuring the longitudinal impedance
is being constructed at IFIC. The measurements will be made during May with
some of the units of the series.
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Main Future projects
ILC: BDS instrumentation studies
LHC: non-linear collimation options for sLHC (SPS experiments) (EUCARD)
IFIMED: Imaging and Accelerators applied to Medicicine
• Monitoring of secondary beams (beam position and size) (CERN; LLR,
CNAO)
• Cyclinacs applications (TERA, CTF3)
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CABOTO: Carbon Boster for Therapy in Oncology
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