Transcript Dump Line

Linac4 Measurement
and Dump Lines
BCC on the
Linac4 Transfer Line Status
Linac4 BCC 14/10/2010
Reminder
LBE Line
LBE Line
LT.BHZ20
LBS Line
LBS Line
Dump Line
LTB.BHZ40
Linac4
Transfer Line
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
Transfer Line
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Linac4 Dump/Measurement Line
Linac4 dump line will be extensively used during Linac4 commissioning.
Regular (although reduced) use during subsequent normal beam delivery
to the downstream machines.
Main usage of the line:
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For Linac4 standalone operation
Dump the beam during optimization of various Linac4 parameters
Dump the beam during Linac4 MDs
For transverse emittance measurements:
Requires different settings for both quadrupoles in the line (to obtain the
value in both planes), steering and sequential operation for 3 screen/camera
systems
During Linac4 commissioning, operation with reduced pulse length
and/or beam current is envisaged.
The dump will not be used for beam interlock purposes.
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
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Status of Linac4 Dump Line
Present Status:
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The layout of the line has been fixed. To be on the safe side, another steerer
magnet should be added between the first screen and the transformer.
First drawings are available.
Equipment specifications have been provided; EDMS document on beam
dump specifications has been released.
Still to be done before installation:
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Final design of magnets, BI equipment.
Final drawings of equipment, supports and layout.
Modified dump design including Fluka simulations. Evaluate dose levels at
equipment positions close to dump and where required.
Application programming at FE and higher layer levels.
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
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LBE Line
The LBE line will be extensively used during Linac4 transfer line
commissioning. After this period, the line will only occasionally be used for
transverse emittance growth control of Linac4 (Linac3?)
Main usage of the line:
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For Linac4 transfer line commissioning
For special MDs
For Linac4 transverse emittance measurements:
Requires different settings for both quadrupoles in the line (to obtain values in
both planes), steering and sequential operation for 3 screen/camera systems
Linac3 transverse emittance measurements: no changes planned
During Linac4 transfer line commissioning, operation with reduced pulse
length is envisaged. Interleaved pulse trains of a few pulses (~10) with the
full pulse length.
The dump will not be used for beam interlock purposes.
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
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Status of the LBE Line
Present Status:
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The layout of the line has been fixed. It will be compatible with ion operation.
Laser scanning of the line done to prepare an integration drawing.
Equipment specifications have been provided; EDMS document on beam
dump specifications has been released.
Still to be done before installation:
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Final screen and camera design (same as for Linac4 dump line), equipment
and support drawings and layout.
Add water-cooling to quadrupoles, exchange power converters
Move steerer dipole.
Dump design.
Beam pipes.
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
6
LBS Line
The LBS line will be extensively used during Linac4 transfer line
commissioning. After this period, the line will only occasionally be used to
check energy and energy spread of Linac4 (and Linac3).
Main usage of the line:
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For final Linac4 commissioning once transfer lines are available
For commissioning of energy painting
For special MDs
For energy and energy spread measurements (Linac4 and Linac3):
Select beam slice with slit and correlate particle energy with position on SEM
grid after spectrometer (same principle as presently, but new equipment)
Operation with reduced pulse length is planned. Interleaved pulse trains
of a few pulses (~10) with the full pulse length.
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
7
Status of the LBS Line
Present status:
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A layout of the line has been proposed, compatible with ion operation. It will be
adapted in case slit dimensions and equipment positions (dump!) would change.
Equipment specifications have been partially provided (depend on final layout);
EDMS document on beam dump specifications has been released, slit
specifications are under approval.
Laser scanning of the line done to prepare an integration drawing.
Still to be done before installation:
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Propose slit and dump designs, check compatibility with RP restrictions.
Finalize SEM grid and spectrometer magnet specifications.
Integration drawings needed in addition to layout drawings.
Prepare software application.
Solve problem of lifting existing/
new equipment over BI line.
An alternative method for the energy
measurement is under study
(next L4/PSB commiss. WG meeting).
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
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Summary
Design: available for the Linac4 dump line and the LBE line. The proposed
design of the LBS line might need some tweaks depending on the dump
position and the slit position/design.
Specifications: have been provided for the three dumps, the slit,
quadrupoles and the emittance measurement screens. SEM grid and
spectrometer magnet specifications need finalisation once all equipment
positions in the LBS line will be fixed.
Outstanding issues: Linac4 and LBE dump designs and Fluka
simulations, spectrometer magnet design, ... The lifting equipment for the
LBS line needs to be upgraded (already in 2012?).
Drawing requests: have been announced.
Software applications: the preparation time for application programming
should not be underestimated (+ action on the two choppers).
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
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Backup Slides
B. Mikulec, T. Hermanns
Linac4 BCC 14/10/2010
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L4 Energy Measurement - Plan B
Interactions of H- ions with rest gas strip electrons
Faraday Cup
Deflection of stripped electrons into analysis line
Slow down/stop electrons with electric field
Measure electrons passing the electrical potential
in Faraday cup as a function of retarding voltage
E
Remaining p, H0, H
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Beam dump
Install corrector magnet to re-use remaining Hbeam
H-
-HV
GND
Interactions with Rest Gas  Stripping of Electrons
Linac4 BCC 14/10/2010
variable
field
e-
p, H0,H11
L4 Energy Measurement - Plan B
Kinetic energy of electrons and H- are correlated
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Same velocity of both particle types
H- ions: ~160 MeV
Electrons: ~87 keV
Retarding voltage is ~equal to kinetic energy
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Some signal loss due to electron absorption at
high voltages plates
Faraday cup signal
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Systematic scanning of electron signal over
suitable voltage range
Energy of electrons: O(1keV)
Measurement principle already established at
BNL Linac
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200 MeV H- beam, 30 mA beam current
Linac4 BCC 14/10/2010
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L4 Energy Measurement - Plan B
Simulation parameters
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Gaussian beams with non-interacting 100,000 particles
Variables: energy (mean and spread), voltage and scanning step width
Differentiation of measured signal  Energy (mean and spread)
Meeting for detailed discussions soon to be organized
Linac4 BCC 14/10/2010
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