Nondestruc,ve!! Beam!Profile!Monitors! in!J7PARC!Accelerators!€¦ · J -PARC MONITOR! Hadron#BT#...
Transcript of Nondestruc,ve!! Beam!Profile!Monitors! in!J7PARC!Accelerators!€¦ · J -PARC MONITOR! Hadron#BT#...
J -PARC MONITOR
Nondestruc,ve Beam Profile Monitors in J-‐PARC Accelerators
T. Toyama KEK/J-‐PARC
2014. 9.22@FNAL
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Japan Proton Accelerator Research Complex
Tokai, Ibaraki
400MeV LINAC 20mA (50mA) 3 GeV RCS
300 kW (1MW)
30 GeV MR 240kW (750W)
MLF
Hadron hall
ν detector Kamioka
← operaTon ←(goal)
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Hadron BT
MEBT DTL/SDTL A0BT
L3BT & dumps
Abort dump line
3-‐50BT
RFQ
MR
ν BT
Beam parameters
ACS
3Ν BT 30 GeV ~ 1.2x1014 ppp / 8 bunches 240 kW (goal: 750kW) σx, σy ~ 1 – 50 π mm·∙mrad length~a few 10 – 200 ns νx, νy ~ 22.40, 20.75 (FX) 22.30, 20.78 (SX)
3 GeV ~ 2.6x1013 ppp / 2 bunches 300 kW (goal: 1MW) σx, σy ~ 50 – 200 πmm·∙mrad length ~ a few 10 – 500 ns νx, νy ~ 6.45, 6.42
181 MeV (400 MeV) H-‐ ~ 20 mA (goal: 50mA) σx, σy ~ 0.1 πmm·∙mrad length ~ 0.1 ns
Charge-‐exchange injecTon with carbon foil
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Gas-‐jet profile monitor in preparaTon
8 BPM 6 SCT 5 FCT 4 WS/BSM 4 BLM
29 BPM 18 SCT 47 FCT 4 WS/BSM 53 BLM
17 BPM 3 SCT 4 FCT 4 WS/BSM 30 BLM
48 BPM 11 SCT 5 FCT 24 WS/BSM 38 BLM 1 VWM
54 BPM(COD) 3 BPM (RF) 4 BPM (fast) 1 BPM (tune) 2 DCCT / SCT 8 MCT, FCT, WCM 2 +1 IPM 7 MWPM 90 BLM (proporTonal) 24 BLM (ionizaTon) 20 BLM (scinTllator) 2 Exciter
MEBT DTL/SDTL A0BT L3BT & dumps
RCS
5 FCT 14 BPM 5 SEEM 50 BLM (proporTonal) 4 BLM (ionizaTon) 1 OTR / Fluorescent screen
Abort dump line
2 BPM 1 SEEM 4 BLM
3-‐50BT
RFQ
MR 2 DCCT 7 FCT 2 WCM 186 BPM (COD, turn-‐by-‐turn) 2 BPM (stripline) 238 BLM (proporTonal) 36 BLM (ionizaTon) 2 BLM (scinTllator) 1 SEEM 5 Luminescence screen 3 IPM 2 Flying wire 2+2 Exciter 1 SEEM
ν BT
1 FCT
*Monitors not counted for beam transport lines to the uTliTes, 3N BT, Hadron BT, ν BT
Hadron BT
42 BPM 21 SCT 41 FCT 4 WS 3 BSM 21 BLM
Monitors in J-‐PARC
ACS
ACS: under construc,on Addi,onal devices are in prepara,on.
3Ν BT
1 FCT 2 BPM 32 BLM 2 Halo monitor
as of 2013
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Ioniza,on Profile Monitors
J -PARC MONITOR IPM
RCS
MR
K. Satoh et al.
Electron collecTon with magnet is foreseen.
InjecTon matching ( ion collecTon mode )
MOPME021 H. Harada et al., IonizaTon Profile Monitor (IPM) of J-‐PARC 3-‐GeV RCS
Electron collecTon for high intensity beams E-‐field uniformity improved
H, V (η=0)
H, V (η=0)
H (η≠0) H (η≠0)
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MCP Multi Anode Mesh
Electrode
GND
HV
+
+
++
++
+ +
++
‐
E
‐
‐
‐
‐
‐‐
‐
‐
‐
‐
‐‐
B
++
Wiggler Magnet
Wiggler Magnet EGA
Resistor
MCP : Micro Channel Plate EGA : Electron Generator Array for MCP gain calibration
The schematic drawing of the IPM wit magnet (Electron collection operating mode)
The positively-charged ions or negatively-charged electrons produced by the beam passing through the residual gas lead to the MCP by the external electric field and the projected beam profile is observed from the MCP signals.
Operating Mode : ‐ Ion Collection with external electric field (E) ⇒ Projected profile is affected by space charge force ‐ Electron Collection with external electric (E) and
magnetic field (B) ⇒ Projected profile is unaffected by space charge force
The external electric field with high uniformity is required to project the beam profile
IPM @RCS
H. Harada, et al., Ioniza0on Profile Monitor (IPM) of J-‐PARC 3-‐GeV RCS, IPAC2013, p.515
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Issue of IPM @ IPAC2012 report
In the beam test we found
21
Mag.) (SteeringPosition Beam Controlled(IPM)Postion Beam Observed
=
Old NewID Potential
[kV]R
[MΩ]Potential
[kV]R
[MΩ]01 3.0 100 4.5 84.402 3.0 100 4.5 84.403 3.0 100 4.5 84.404 3.0 100 3.0 56.305 3.0 100 3.0 56.306 3.0 100 3.0 56.307 3.0 100 3.0 56.308 3.0 100 3.0 56.309 3.0 100 3.0 56.310 3.0 100 2.5 46.911 3.0 100 2.4 45.012 3.0 100 1.2 22.513 3.0 100 1.2 22.514 3.0 100 0.6 11.315 3.0 100 0.6 11.3
Upgrade concept IPM @ IPAC2012 report
We found that this is caused by non-uniformity of external electric field from 3D electric field calculation .
Table 1: Old and new electric potentials and resistors between electrodes
New electric potential by the connected resistors
x
y
z=0 x
y
z=0
Old Ex New Ex
The new electrode structure, electric potential patterns and MCPs were replaced and upgraded during summer shutdown 2012
IPM @RCS
H. Harada, et al., Ioniza0on Profile Monitor (IPM) of J-‐PARC 3-‐GeV RCS, IPAC2013, p.515
J -PARC MONITOR
Ion collecTon mode
Electron collecTon mode
IPM @RCS
CalibraTon with the beam shimed in Δp/p Dispersion @IPM ηx = 4.054m
!f/f (!p/p)
time[ms]2 100
An example of the data (ion collecTon mode)
Beam center (Gaussian fit)
Ion collecTon mode
Electron collecTon mode
Comparison to the expected value
Ra,o = 0.934
Ra,o = 1.116
H. Harada, et al., Ioniza0on Profile Monitor (IPM) of J-‐PARC 3-‐GeV RCS, IPAC2013, p.515
Δp/p = -0.6% Δp/p = 0.6%
J -PARC MONITOR IPM @ MR K. Satou et. al
130mm
35kV 33kV
EGA
MCP
Electrode
Voltage divider 100MΩ resister
Ceramic bushing
HV feedthrough
Cross sec,on of V-‐IPM
Ion collection with HV • 50kV operation at the maximum
Electron collection with magnetic field • Required for 0.75MW beam profile measurement ⇒ future plan
Micro Channel Plate (MCP) for signal read out device • 2 stage MCP assembly with 32 ch strip anode • Active area: 31×81 mm2 or ~20x120 mm2 • Width of each anode: 1.0 - 2.5 mm • Gain: ~10 6
Calibration devise for MCP gain balance • Electron generator arrays ⇒ Photonis Ltd.
Horizontal plane: 1 IPM (η=0) Vertical plane: 1 IPM (η=0) Arc-C section: 1 IPM (η=0.4m)
Average=100time
Anode position (mm)
1000turn
999turn
998turn
Turn by turn beam profile
80 mm
997turn5μs
Average=100time
Anode position (mm)
1000turn
999turn
998turn
Turn by turn beam profile
80 mm
997turn5μs
LPF: ~5µsec DigiTzer: 200MHz, 100kS/s, 1 Mwords K. Satou, et al., "IPM SYSTEMS FOR J-‐PARC
RCS AND MR", HB2010, p.506
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K. Satou et al., "IPM SYSTEMS FOR J-‐PARC RCS AND MR", HB2010, p.506
IPM @ MR
Tme
Tme
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Ion collec,on mode: beam space charge potenTal deforms the profile
Electron collec,on mode: curious signal behavior
K. Satou, HB2010
IPM @ MR
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Improvement at present: Preparing magnets for electron collecTng mode
Guiding field for electron collecTon
Orbit correcTon
Orbit correcTon
IPM @ MR
J -PARC MONITOR
Summary of IPMs RCS
Ion collecTon mode with external electric fields The uniformity of electric field was significantly improved.
Electron collecTon mode with external electric and magneTc fields A simple tracking code suggests that the posiTon shim was caused by
erroneous magneTc field component of Bx. To be corrected by beam-‐based calibraTon. Absolute measurements are performed amer fast extracTon.
Emioance measurement uTlizing the MWPM (Harp) and Quads. MR
UTlized for MR injecTon matching. Electron collecTon mode
Magnets are ready to install. Mystery: where dose the excess electron come from?
IPM @RCS & MR
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Flying-‐Wire Profile Monitor (MR)
J -PARC MONITOR Flying Wire @MR
S. Igarashi, et al., "BEAM PROFILE MEASUREMENT USING FLYING WIRE MONITORS AT THE J-‐PARC MAIN RING", IPAC2011, p. 1239
• One horizontal, one ver,cal • Carbon wire of 7μm diameter • Wire speed: 10m/s • < 4.4 x 1013 p / 2 bunches
RCS MR
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Flying wire (Hor.) Flying wire (Ver.)
Flying Wire
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!"#$%"&'()*+,(-*.#"/),0*12,(03#,-,&'*(&4*5$-3)(6"&7
• 89:,;<*===*18*>3&?@*$&A,?6"&7**• B)C$&D*E$#,*-,(03#,-,&'0*('*F;G;H*-0*(&4*F;G;8H*-09*• 5IJK*0$-3)(6"&*L$'@*$&$6()*4$0'#$>36"&*"M*;NO*---#(4**"M*!"#$%"&'()*8P*
,-$Q(&?,*(&4*8RO*M"#*S,#6?()*8P*,-$Q(&?,9
Flying Wire @MR
S. Igarashi, et al.
J -PARC MONITOR
!"#$%&'()"&*(+#,-'".(
/0"&.1#"*"23(&24(56*1'&$,27• 589:(.6*1'&$,2(;63<(626$&'(46.3#6=1$,2(,>(?@A(***#&4((,>(
B,#6C,23&'(DE("*6F&2%"(&24(DGA(>,#(!"#$%&'(DE("*6F&2%"H
Flying Wire
S. Igarashi, et al.
J -PARC MONITOR
Summary of the flying wires The flying wire profile monitors are uTlized for the tuning
and beam studies as absolute measurements.
The carbon wire was broken during measurement of the beam@4.4x1013 ppp/2 bunches. The reason and remedy are under invesTgaTon.
Flying Wire
J -PARC MONITOR
Gas-‐Jet Profile monitor (MR)
J -PARC MONITOR Gas-‐jet Profile Monitor @NIRS
Gas-‐sheet profile monitor at NIRS O2 gas Detect ioniza,on by MCP
Y. Hashimoto et al., Proc. of EPAC2002, p.1900, NIM A527 (2004) 289–300.
J -PARC MONITOR
In preparaTon for the J-‐PARC MR Target: Nitrogen Molecule fast decay Tme (< 100 ns) intense visible luminescence light (λ=390 nm)
Gas-‐jet Profile Monitor @J-‐PARC
Y. Hashimoto et al., "DEVELOPMENT OF A BEAM PROFILE MONITOR USING A NITROGEN-‐ MOLECULAR JET FOR THE J-‐PARC MR", IBIC2013, p.848.
J -PARC MONITOR Jet Generator
Test Bench
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J -PARC MONITOR
J -PARC MONITOR
J -PARC MONITOR
Summary and Prospect Measured the transverse 2D profile of the carbon ion beam
with oxygen jet (85mm wide, 1.3 mm thick, 1x10^-‐4 Pa)@ NIRS. New set with nitrogen jet is in preparaTon for J-‐PARC.
➢ Improve • target thickness • target uniformity
➢ Find the best/beoer place to install:
• low radiaTon background (one candidate ~50 mGy/week @220 kW operaTon) • beam dynamics point of view
→ installaTon in the next summer shut-‐down
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Possible Collabora,on
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• Are there any possible R&D issues?? IPM FW Gas-‐jet
• Mini-‐workshop on the nondestrucTve profile monitors of both laboratories in this or next fiscal year?