Week and Workshop
IFMIF: Project Status Convergences with SPIRAL2 Alban Mosnier
Alban Mosnier
January 26 - 29, 2009
CEA-Saclay, DSM/IRFU
SPIRAL2 Week
Memorial, Caen
page 1
IFMIF Principles Week and Workshop
Test Modules 2 x 125 mA D+ CW at 40 MeV
Typical reactions: 7Li(d,2n)7Be, 6Li(d,n)7Be, 6Li(n,T)4He
Accelerator based neutron source using the D-Li stripping reaction ⇒ intense neutron flux with the appropriate energy spectrum
Alban Mosnier
January 26 - 29, 2009
Beam footprint on Li target 20cm wide x 5cm high (1 GW/m2) SPIRAL2 Week
Memorial, Caen
page 2
IFMIF EVEDA project in the framework of an agreement between Euratom & Government of Japan
Week and Workshop
a 6-year program has been launched in the middle of 2007, called EVEDA Engineering Validation and Engineering Design Activities includes 3 systems: Accelerator, Target and Test Facilities The objectives of the accelerator activities are two-fold: to validate the technical options with the construction of the Prototype Accelerator: full size IFMIF accelerator from source to 1st DTL to be installed and commissioned at full beam current at Rokkasho (Japan) to produce the detailed integrated design of the future IFMIF Accelerator (including complete layout, safety analysis, cost, planning, etc) to be ready to start the IFMIF facility construction Components of the prototype accelerator provided by European institutions CEA, INFN, CIEMAT, SCK-CEN: Injector, RFQ, DTL, transport line and 1.2 MW beam dump, 175 MHz RF systems, local control systems and beam instrumentation Building at Rokkasho BA site, supervision of the control system, RFQ couplers, provided by JAEA Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 3
Beam Dynamics
Coordinator: P. NGHIEM (Cea) Week and Workshop
optimisation
beam occupancy wrt pipe aperture
1. Injector
3. DTL
O. Delferriere (Cea)
N. Chauvin (Cea)
IFMIF accelerator
PROTOTYPE accelerator Simulations all along the linac from source to target/beam dump 2. RFQ
beam loss control
4. HEBT M. Comunian (Infn)
Alban Mosnier
January 26 - 29, 2009
beam characterization beam expander to BD SPIRAL2 Week
C. Oliver (Ciemat)
Memorial, Caen
page 4
responsible Lab: CEA - Saclay Coordinator: R. GOBIN
Week and Workshop
INJECTOR goal • to deliver a 100 keV deuteron beam high intensity (140 mA) high quality (0.25 π.mm.mrad) matched to the RFQ entrance high reliability
Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 5
Ion Source ECR source selected design based on SILHI (Electron Cyclotron Resonance)
Week and Workshop
H+
source
magnetron 2.45 GHz
Studies focused on ... • extraction system (better maching for D) • engineering design (compact HV platform) • efficient radiation shielding
4 electrode extraction system
• fast beam interlock to implement < 10 µs
4-electrode system Emax = 101 kV/cm
Ion Source Extraction ... 140 mA D+ ⇒ 175 mA total beam (D+ 80%, D2+ 15%, D3+ 5%) Axcel & Opera2D simulations to optimise # electrodes (4) aperture ø (12 mm) Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 6
Low Energy Beam Transport • High intensity beam interaction with residual gas ⇒ space charge compensation effects
Week and Workshop
• Emittance growth (mainly due to transport and not extraction)
LEBT simulations
New code developed to calculate space charge compensation
challenging parameters to meet at the RFQ entrance:
0.25 π.mm.mrad
beam emittance ⇒ injection of gas for better compensation krypton 4.10-5 hPa beam matching conditions ⇒ high focusing & short line
Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 7
Status and next steps beam dynamics calculations just completed (longer than expected)
Week and Workshop
Critical Design Review held on October 14, 2008 (external Review Committee) Next steps • End of detailed drawings • Procurements
- HVPS - Magnets, - Control system equipment VME crates, PLC ... - Mechanics HV cage, plasma chamber... • Start integration at Saclay
⇒ Start of beam tests in April 2010 Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 8
responsible Lab: INFN - Legnaro Coordinator: A. PISENT
Week and Workshop
Radiofrequency Quadrupole goal • to bunch the dc beam from the injector • to accelerate the beam from 0.1 to 5 MeV high transmission (low losses) minimal length with reasonable field 4-Vanes
High current CW operation
Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 9
RFQ Beam Dynamics Week and Workshop
Design parameters Input energy Output energy Input Current Input emittance Frequency Phase adv. trans long
100 keV 5 MeV 130 mA 0.25 π mm.mrad 175 MHz 220 deg/m 90 deg/m
Optimisation of the RFQ • reduced length (9.8 m) & power consump
• beam loss along the RFQ under control Criteria for the 3 successive sections
• Analytic law for the voltage with a smooth increase in the accelerator section
• Larger acceptance in accelerator section •
to reduce losses at high energy Physical aperture "a" minimal at GB end playing the role of beam collimation to prevent for beam loss downstream
• High focusing strength B to keep the beam •
in the linear part of the focusing fields Peak surface electric field limited to the reasonable value of 1.8 x Kilpatrick
B = qV!2 mc 2 r02 Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 10
RFQ Mechanical Design 9 modules (1.1m) flanged together each module made of 2 Cu blocks 1 .1
x0
x0 .4 1
Week and Workshop
.4 1
RF
square cross section
S T PU N I
⇒ large free surfaces available for couplers, plungers, vacuum ports
Assembling: Brazing technique
Δf -0.52 KHz vane tip 4,6 µm
vacuum pipe
Cooling: separated ducts for vanes & for cavity skin am e B
⇒ small deformations and linked frequency shifts under RF power heating and water cooling
IN
Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 11
RFQ - beam losses Week and Workshop
Main concern: activation ⇒ extensive multi-particle simulations • RFQ transmission ~ 98.5% (input beam: waterbag distribution) • Losses above 1MeV kept at low level Sensitivity to input beam “best case”
“worst case”
waterbag
gaussian
0.25 π mm mrad 0.30 π mm mrad Shaper
GB
Accelerator
Tr = 98.5 %
Tr = 92.1 %
M. Comunian calculations Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 12
responsible Lab: CEA - Saclay CIEMAT/CEA collaboration, Coordinator: F. ORSINI
Week and Workshop
Drift Tube Linac goal • to accelerate the 125 mA CW beam to 40 MeV for IFMIF to 9 MeV for prototype accelerator while preserving the emittance & minimizing beam halo, beam loss
Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 13
n.c. DTL replaced by s.c. HWR DTL MS
LEBT
Ion source
Li Target
s.c. HWR Linac
RFQ
BA Steering Committee decision May 2008
Advantages • length reduction ~ 10 m • operation cost saving ~ 6 MW • higher flexibility & reliability • mature technology better suited to existing teams & industries • less sensitive to machining & assembly errors
Q RF IS
E +L
+M
S
BT
conservative approach Moderate gradient @ 4.5 MV/m Large aperture Alban Mosnier
Week and Workshop
4 cryomodules
@ 40-50 mm
January 26 - 29, 2009
. n.c
TL D rez a Alv
Cryomodules Cavity β Cavity length (mm) Beam aperture (mm) Nb cavities / cryostat Nb solenoids Cryostat length (m) Output energy (MeV)
SPIRAL2 Week
B HE
T
4 cryomodules 2 resonator families 1 0.094 180 40 1x8 8 4.64 9
Memorial, Caen
2 0.094 180 40 2x5 5 4.30 14.5
3&4 0.166 280 48 3x4 4 6.03 26 / 40
page 14
Conceptual design Resonator & Tuner Week and Workshop
Geometry optimisation ⇒ peak surface fields sufficiently reduced (determine the maximum reachable accelerating field) Ep/Eacc=4.4 & Bp/Eacc=10.1 Tuning method chosen: plunger at the opposite of the coupler port, in a region of high electric field (tuning range easily achieved) Tuning system actuator mechanical part under progress
beam
Power coupler
Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 15
Conceptual design cryomodule Week and Workshop
• Conceptual design for: cold mass support, alignment system, cryogenic pipes, vacuum pipes, interfaces, connections with all services
Vacuum tank He phase separator Tuning system
Collecting volume: large enough to well separate gas and liquid
Cavity Support
Exhaust pipes : diameter & path for He 2-phase flow
Supply pipe + tank : minimum pressure drop
Coupler
Solenoid magnetic design with passive shielding
Horizontal supply pipe: diameter large enough to be quasi isobaric on its length
On-axis field profile with passive shielding
• Conceptual design for: He cooling (forced flow mode)
• Conceptual design for: Solenoid (passive shielding) Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
Memorial, Caen
page 16
responsible Lab: CIEMAT CIEMAT/CEA/SCK•CEN collaboration
RF Power Systems With the SC DTL solution, the
Week and Workshop
coordinator: P. Mendez
150
Cavity Power (kW) 125
RF Power system changes drastically
100 75
Standardization: identical RF sources
50
used for all components (RFQ, Bunchers, HWR)
Resonator index 0
10
20
30
40
with 2 different RF power ratings : 20 x 105 kW and 32 x 200 kW only 1 type 400 kW HVPS (feeding 1 x 200 kW or 2 x 105 kW RF power units) 8 x 200 kW RF Chains
2 x 105 kW RF Chains
RFQ
MS
8 x 105 kW RF Chains
12 x 200 kW RF Chains
175 MHz
100 keV
Alban Mosnier
January 26 - 29, 2009
CM 1 5 MeV
SPIRAL2 Week
~~
INJ
CM 4
9 MeV
Memorial, Caen
40 MeV
page 17
RF System implementation Week and Workshop To optimize space, improve maintenance and availability symmetric modular system composed of removable modules including two complete amplifiers each ⇒ compact & fast repair in case of failure LLRF: Digital Commercial Board cPCI with 8 ADCs, 8 DACs and FPGA
Analog Front Ends for Downconversion (RF to IF) and Upconversion (DC to RF) Timing systems: 195 MHz (175 + 20) for downconversion synchronized with digital 80MHz clock for digital acquisition 195MHz
175MHz
Timing Systems (Digital + Analog) Host PC Windows
80 MHz
cPCI Bus
Analog Front End
Vacuum & Arcs Interlocks
Digital I/O
Digital Board
FPGA
8 ADCs 80 MHz
Digital IQ Demodulation and Control Loops
Down Conversion
8 DACs IQ Ctrl 80 MHz DC
Pin Switch
Analog Front End Up Conversion
175 MHz
Tuning Loop
IF
175 MHz RF Reflected Circulator Voltage 1 (175MHz) RF Reflected Cavity Voltage 1 (175MHz) RF Forward Cavity Voltage 1 (175 MHz)
CAVITY
RF Cavity Voltage 1 (175 MHz) RF Reflected Circulator Voltage 2 (175MHz) RF Reflected Cavity Voltage 2 (175MHz) RF Forward Cavity Voltage 2 (175 MHz) RF Cavity Voltage 2 (175 MHz)
Alban Mosnier
January 26 - 29, 2009
SPIRAL2 Week
CAVITY
Memorial, Caen
page 18
HEBT & Beam Dump - P. A. responsible Lab: CIEMATcoordinator: Beatriz Brañas
Week and Workshop
• Diagnostics-Plate for beam characterization • 20° dipole magnet to avoid neutron backstreaming • 8 quadrupoles for beam matching & expanding
Beam Dump
9 MeV - 1.125 MW
• cartridge ø=30 cm, L=2.50 m conical shape + cyl. input scraper ø=30 cm • beam facing material activation & thermo-mechanical analysis copper (minimum stresses)
Beam Dump
movable Gamma shield
• cooling system axial flow in counter-beam direction through annular channel Beam of varying width Tin=20 ºC, p=6 bar, v
