J -PARC MONITOR  

Nondestruc,ve    Beam  Profile  Monitors  in  J-­‐PARC  Accelerators  

 T.  Toyama  KEK/J-­‐PARC  

 2014.  9.22@FNAL  

J -PARC MONITOR  

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)  

J -PARC MONITOR  

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

J -PARC MONITOR  

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

J -PARC MONITOR  

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)

J -PARC MONITOR  

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

J -PARC MONITOR  

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

J -PARC MONITOR  

K.  Satou  et  al.,  "IPM  SYSTEMS  FOR  J-­‐PARC  RCS  AND  MR",  HB2010,  p.506

IPM  @  MR  

Tme

Tme

J -PARC MONITOR  

Ion  collec,on  mode:    beam  space  charge  potenTal  deforms  the  profile  

Electron  collec,on  mode:    curious  signal  behavior  

K. Satou, HB2010

IPM  @  MR  

J -PARC MONITOR  

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

J -PARC MONITOR  

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

J -PARC MONITOR  

Flying  wire  (Hor.)   Flying  wire  (Ver.)  

Flying  Wire  

J -PARC MONITOR  

!"#$%"&'()*+,(-*.#"/),0*12,(03#,-,&'*(&4*5$-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  

J -PARC MONITOR  

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

J -PARC MONITOR  

Possible  Collabora,on  

J -PARC MONITOR  

•  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?