Accelerator R

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Accelerator RD 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 DYNAMICS EXPERTISE
BEAM INSTRUMENTATION

• Optics design
• Non-linear dynamics studies
• New instrumentation techniques
• Commissioning

- CALCULATION

• Electromagnetic analysis
• Electric circuits electronics
• Mechanical analysis

- 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 BPMs 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
extraction
diagnostic section
wire scanners
OTR monitor
(OTR)
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
QM7R quadrupole
BS1X septum magnet
At the extraction (x2.25 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
close the bump in the DR
OTR monitor
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ATF and ATF2 Experimental Work (Dec07-May08)
Measurements simulatios for different
horizontal extraction positions
Beam size at the OTR/XSR
Beam size at the OTR/XSR
(28th May08)
(19th Dec07)
Measurements during different shifts
- 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 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
extraction
diagnostic section
wire scanners
OTR monitor
(OTR)
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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ATF and ATF2 New Multi-OTR System
diagnostic section
extraction
OTR1X
OTR0
OTR1
OTR2
OTR3
OTR4
The location of the OTRs 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 BPMs 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 BPMs supports with micromovers for
FONT4
Proposal

• BPMs 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 Dec09 (ATF2 shutdown)
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Main Ongoing Projects
CLIC-CTF3 BPMs 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
BPSs and the quadrupoles
BPS Prototype Inductive Pick-up (IPU)
2.25 cm
TBL beam time structure
Inductive sensors PCB
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CTF3 BPMs for the Test Beam Line
BPS Prototypes
BPS1 Prototype Performance
BPS1 Sensitivity and Linearity Parameters 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), sV (/- 5 mm) 78 µm
H overall precision (accuracy), sH (/- 5 mm) 109 µm
BPS1 Characteristic Output Levels BPS1 Characteristic Output Levels
Sum signal level, S 16.5 V
Diff signals levels, ?Vmax, ?Hmax 8.25 V
Centered beam level, Vsec (xV 0, xH 0) 4.125 V
BPS1 Frequency Response (Bandwidth) Parameters BPS1 Frequency Response (Bandwidth) Parameters
S low cut-off frequency, flS 1.76 KHz
? low cut-off frequency, fl? 282 KHz
SCal low cut-off frequency, flS Cal 1.76 KHz
?Cal low cut-off frequency, fl? Cal 180 KHz
High cut-off frequency, fh gt 100 MHz
High cut-off frequency Cal fhCal gt 100 MHz
BPS1 Pulse-Time Response Parameters BPS1 Pulse-Time Response Parameters
S droop time const, tdroopS 90 µs
? droop time const, tdroop? 564 ns
SCal droop time const, tdroopS Cal 90 µs
?Cal droop time const, tdroop? Cal 884 µs
Rise time const, trise lt 1.6 ns
Rise time const Cal, trise Cal lt 1.6 ns
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 BI-PI 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.
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 BPMs 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.
BPS2 and BP3 Series Performance
DAQ equipment for all the setup signals and
micromovers controller
Sensitivity and Linearity Parameters BPS2 BPS3
V Sensitivity, SV 43.16 m-1 43.70 m-1
H Sensitivity, SH 44.60 m-1 42.10 m-1
V Electric Offset, EOSV -0.67 mm -0.84 mm
H Electric Offset, EOSH 0.50 mm 0.52 mm
V overall precision (accuracy), sV (/- 5 mm) 89 µm 94 µm
H overall precision (accuracy), sH (/- 5 mm) 90 µm 98 µm
Characteristic Output Levels
Sum signal level, S 16.5 V 16.5 V
Diff signals levels, ?Vmax, ?Hmax 8.25 V 8.25 V
Centered beam level, Vsec (xV 0, xH 0) 4.125 V 4.125 V
Frequency Response (Bandwidth) Parameters
S low cut-off frequency, flS 2.90 KHz 1.70 KHz
? low cut-off frequency, fl? 271 KHz 275 KHz
SCal low cut-off frequency, flS Cal 2.80 KHz 1.70 KHz
?Cal low cut-off frequency, fl? Cal 163 KHz 171 KHz
High cut-off frequency, fh gt 100 MHz gt 100 MHz
High cut-off frequency Cal fhCal gt 100 MHz gt 100 MHz
Pulse-Time Response Parameters
S droop time const, tdroopS 55 µs 93 µs
? droop time const, tdroop? 587 ns 579 ns
SCal droop time const, tdroopS Cal 57 µs 93 µs
?Cal droop time const, tdroop? Cal 976 µs 931 µs
Rise time const, trise lt 1.6 ns lt 1.6 ns
Rise time const Cal, trise Cal lt 1.6 ns lt 1.6 ns
Low-frequency wire set up at the IFIC labs
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 (gt250 mA) to avoid the low current
effects in the test measurements.
3D view of the Low-frequency wire set up
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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)
  CABOTO Carbon Boster for Therapy in Oncology

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Thanks for your Attention