status of the rare isotope reaccelerator facility reaepaper.kek.jp/pac2013/talks/fryba2_talk.pdf ·...

Status of the Rare Isotope ReAccelerator Facility ReA

, Slide 1

Facility ReAD. Leitner

on behalf of the ReA team atMichigan State University

Outline

• Introduction

• ReAcclerator facility

• Commissioning Results and Status

• First radioactive ion beam delivery

NSCL/FRIB Laboratory

, Slide 2

FRIB Accelerator Complex Subsystems

ReAccelerator Facility

, Slide 3J. Wei, NA-PAC'13 FRYBA1

Isotope production reaction mechanisms [1]

ISOL –Isotope Separator On-Line (target “spallation” or fission)– Light ion-induced “spallation” or fission of heavy targets – Isotopes must diffuse from hot targets and effuse to an ion source– Typical beams ~100-1000 MeV protons; typical targets Ta & UC– Photofission using high power electron linac

Most post accelerator facilities are based on

Stopped

, Slide 4

Production Accelerator

Thick Hot Target

Target/Ion Source

Stopped Beams

PostAccelerator

Isotope/Isobar Separator

Several facilities around the world:Rex-Isolde, Spiral, ISAC, EXYPT, SPES,EURISOL …

• Very intense beams of many elements, especially noble gases and alkalis

• Weak beams of refractory and chemically active elements

D. Leitner NA-PAC 2013, slide 4

Isotope production reaction mechanisms [2]

• In-flight heavy-ion fragmentation or fission on a l ight target– Fragments of the beam are kinematically forward directed at ~beam velocity– Rare isotopes are separated physically; no chemical dependence– Typical heavy ion beams are 18O- 238U at 200-2000 MeV/u; typical targets Be or C

Fragment Separator

Stopped BeamsGas or Gas or

Solid Fast • Separated beams of any

species including refractory and

, Slide 5

ReA at MSU is the first post-accelerator coupled to a fragmentation facility

Production Accelerator

SeparatorPost

AcceleratorStopper

Solid Stopper

Fast Beam

Thin Production Target

species including refractory and chemically active elements and isotopes with very short half-lives, even isomers

• Needs gas catcher or solid stopper for post acceleration


CCF Is The Only Facility In The World That Provides Fast, Stopped, And Reaccelerated Beams Of Rare Isotopes

Gas StopperK500 Cyclotron

MoNALISA

Sweeper Magnet

SECAR (design)JENSA

ANASEN, FSU SuNCFFDJANUS..

Momentum Compression Beam Line)

BECOLA

AT-TPC

Cycstopper off line commissioning

20 meter

ReA3 Hall

ReA6-12Hall

LEBIT,Minitrap

, Slide 6

Fast BeamsFast Beams Gas StopperGas Stopper Stopped beamsStopped beams Reaccelerated BeamsReaccelerated Beams

Space for future expansion of the science program

ReAccelerator Facility

A1900 Fragment Separator

K1200 Cyclotron

SEETFSeGAHiRATriplex Plunger CAESARLENDAGRETINA (DOE national user facility)

BCSNERO DDASCAESAR

RFFS

S800


In-flight Fragmentation Offers A Wide Variety Of Rare Isotopes

At the Coupled Cyclotron Facility at MSU (≈10 years of operations)

more than 1000 RIBs have been produced and more than 870 RIBs have

been used in experiments with > 90% availability

Average experiment: primary beam 120 hrs, several secondary RIB beam changes

ReA SC Post-Accelerator – 3 stages(41 SC SRF cavities)

Achromatic Mass Sep

RT RFQ80.5 MHZ RT RFQ

MHB

1+→n+

Mass

separation

Gas

Stopper

Experiments

ReA3 (15 cavities)(2014)

ReA6(+10 cav.)

(2015)

ReA12(+16 cav.)proposed

ReA12(+16 cav.)proposed

Fast

RIB

, Slide 8

Requirements : Variable energies 300keV/u – 12MeV/u

Ionization efficiency for all elements

> 20 % EBIT charge breeder + high efficiency linac

Beam rate capabilities 108 ions/sec Hybrid EBIS/T charge breeder

High beam purity A1900, EBIT CB, Q/A

Low energy spread, short pulse length

1keV/u, 1nsec Multiharmonic external buncher and tight phase control in SRF linac

Stopper RIB


Rare Isotope Beam Production

40Ca primary beamAt 140MeV/u

Production rate ~1.3E5 PPS/pnA,

Purity for K-37 ~ 50%

dp/p = 0.5%D. Leitner NA-PAC 2013, slide 9

Rare Isotope Beam Thermalization : RIB Beams Gets Further Purified

ANL 1.2 m long linear gas cellHigh purity helium: ~ 90 Torr, -50CThermalizes RIB ions to < 1eVSingly and doubly charged

Rat

e (c

ps)

Variable degrader and wedge for further purifying the beam

94% 37K+

Second gas catcher or cyclotron stopper

Electrostatic Transport Line at 60keV

Analyzing Magnet

mass

D. Leitner NA-PAC 2013, slide 10MOPMA07, J.A. Rodriguez et al, “The D-Line Project at MSU”

Rare Isotope Beam Thermalization Station

Commissioned 2012/2013


ReA Design Choices: EBIT Charge Breeder

0.085 moduleFY14

0.041 modulesRT RFQ

MHB

Achromatic Mass Separator

Pilot source for linac tuning

n+ RIB beamn+ RIB beam

EBIT1+ RIB beam


EBIT:

• Short breeding time• High ionization efficiency• Charge state flexibility• Low beam contamination• 0.5 ≥ Q/A ≥ 0.2

Charge Breeding In The EBIT Source

Radial electron-beam

Highly charged ions

Trap electrodes

Magnetic field

Electron

collector

Electron

gun

Electron

beam

Continuous injection and

accumulation (~100 ms)

A+

Pulsed extraction (100 µs to ms)

AQ+

q+ q+

V1+1+

2+2+

Pulsed extraction

1+1

Radial electron-beam

space-charge potential

Axial potential well from the trap electrodes

Over-the-potential barrier injection Lower-the-barrier extractionV

Continuous injection D. Leitner NA-PAC 2013, slide 13

EBIT Background Spectrum And Selection Of 37K Charge States

200

250

300

350

400

Ana

lyze

d C

urre

nt [

pA]

H2+

16O

7+

14N

6+

16O

6+

14N

5+

Ar10

+ ,12

C3+

16O

5+

14N

4+

0

50

100

150

200

2 2.5 3 3.5 4

Ana

lyze

d C

urre

nt [

pA]

Mass/Charge Ratio (A/Q)

37K

18+

37K

17+

37K

16+

12C

6+

40A

r16+

37K

19+

37K

15+

37K

14+

37K

13+

37K

12+

37K

11+

37K

10+

37K

9+

12C

4+

40A

r14+

16O

4+, 40

Ar

40A

r13+

40A

r12+

40A

r11+


Background ion intensities from the charge breeder in the region of interest are less than 1 pA

10

100

Ana

lyze

d C

urre

nt [

pA]

K19

+

37K

18+

37K

17+

37K

16+

H2+

15N

7+

16O

7+

14N

6+

12C

6+

40A

r17+

18+

0.1

1

1.8 1.9 2 2.1 2.2 2.3 2.4

Ana

lyze

d C

urre

nt [

pA]


37K

37 37 37

13C

6+

40A

r18+


0.085 moduleFY14

0.041 modulesRT RFQ

MHB

Q/A

Pilot source

ReA Design Choices: RT -RFQ With External Buncher And High Efficiency SC -Linac

n+ RIB beam

, Slide 16

EBIT1+ RIB beam

SRF LINAC� 80.5 MHz RF frequency�Flexible energy range (deceleration 300keV/u to maximum linac energy in small steps�External multi harmonic buncher to minimize the longitudinal emittance


Room Temperature Radio Frequency Quadrupole (RFQ )

• Pulsed operation (160kW, 25%)• Energy Boost: 12 keV/u - 600 keV/u• 4-rod structure, 92 cells, 3.3 m long• Buncher : 80.5MHz, 161MHz, (241.5 MHz)• Nom 82 % beam capture measured

Longitudinal acceptance (white area)

Beam at the entrance of

MHB

Beam at the entrance of RFQ

0

100

200

300

400

500

600

700

880 890 900 910 920 930 940 950

Cou

nts

(arb

.uni

t)

nsec

FWHM0.52 nsec

12.54 nsec

Beam bunch after RFQ


Q. Zhao et al., PAC’07; D. Leitner et al, PAC’11; W. Wittmer et al., NA-PAC’13 (MOPSM07)

Compact Superconducting Linac With 2 Types Of Quarter Wave Resonators

• 7 β=0.041 cavities are in operation since 2010 with excellent performance and stability

• Routinely operated at 160% of the specified gradient

Measured Phase and Amplitude Stability

Cavity Phase Std Amplitude Std

, Slide 18

Cavity Phase Stddev (deg)

Amplitude Stddev (%)

82 0.149 0.025 %

84 0.207 0.009 %

85 0.043 0.018 %

88 0.14 0.013 %

89 0.06 0.020 %

91 0.248 0.046 %


D. Leitner et al., SRF'2011

Compact Superconducting Linac With 2 Types Of Quarter Wave Resonators

• Cryomodule 3 will be installed and commissioned in the in 2014

• β=0.085 cavities were redesigned to reliably provide high gradient acceleration fields

cavitysolenoid

1010

SC248SC249SC251SC252

0 10 20 30 40 50

β = 0.085 quarter-wave resonator test results

Epeak

(MV/m)

• Eleven β=0.085 cavities have been tested (all tested well above specifications)

• CM4 (FRIB prototype) 2015, novel bottom up design

solenoid

D. Leitner NA-PAC 2013, slide 19FRYBA1, J. Wei et al, “Progress towards the Facility for Rare Isotope Beams”A. Facco et al., IPAC'2012

108

109

0 2 4 6 8

SC252SC253SC254SC256SC255

Qua

lity

Fac

tor

Eacc

(MV/m)

ReA6

(4K)ReA3 (4K)

4K

Diagnostic Systems Are Very Challenging For RIB Post-accelerators (Dynamic Range 10 pps To 1012 pps)

1, 2, 3, 4, 5, 6, 10

Diagnostics

1 FC

2 Slit profile monitor

3 Viewer, MCP or crystals

4 Bunch lengths, timing

5 Slits, aperture

6 Attenuators

1, 2, 4, 5,7 1, 2, 3 4,5

7,12

12 1, 2,

1, 2, 3, 4, 5, 6

1,2, 4,9,

11, 7

1,3,8

1,2, 3,7,8

6 Attenuators

7 Detectors (decay, scattering, in beam)

8 MCP, TOF

9 Pepperpot

10 Emittance Scanner

11 Energy defining slits

12 BPM

12 1, 2, 5, 4

1, 11

1, 2, 5 4, 7

1,3,8

ReA linac has a lot beam diagnostics to support the wide range of beam intensities


ReA Beam Line Is Well UnderstoodDesign compares well with the actual tuning paramet ers of the beam line

EBIT CB

RFQ

CM2

CM3 (2014)

CM1SECAR

AT-TPCD-LineN4 Stopped beams

First RIB beam delivered

Low Energy Experimental hall

A1900

Beam Envelope

MOPSM07, W. Wittmer et al.

Linac transmission RIB beams≈ 70%

The ReA Linac (CM1+CM2) Was Characterized Using Stable Beams

• Absolute energy calibration of ReA using 992 keV Al(p,γ) resonance

• Linac was tuned in 2keV energy steps• Measured energy spread of 0.5% FWHM is close to

predicted value

L. Ling-Ying et al., manuscript under preparationD. Leitner NA-PAC 2013, slide 22

CAESAR Detector Array

For Rare Isotope Beam Operations Pilot Beams Are Used To Pre-tune The Linac

EBIT CB

RFQ

CM2

CM3 (2014)

CM1SECAR




0

10

20

30

40

50

0 20 40 60 80 100

Cou

nts

Energy [MeV]

241Am calibration source

16O5+ 40Ar13+

87Rb28+

A1900


Pilot Beam


EBIT CB

RFQ

CM2

CM3 (2014)

CM1SECAR




0

10

20

30

40

50

0 20 40 60 80 100

Cou

nts

Energy [MeV]


16O5+ 40Ar13+

87Rb28+

A1900


Pilot Beam

Background Ion from EBIT


EBIT CB

RFQ

CM2

CM3 (2014)

CM1SECAR




0

10

20

30

40

50

0 20 40 60 80 100

Cou

nts

Energy [MeV]


16O5+ 40Ar13+

87Rb28+

A1900


Pilot Beam

Charge Bred BeamRb+ → Rb28+

from the EBIT


EBIT CB

RFQ

CM2

CM3 (2014)

CM1SECAR




A1900

15N7+, A/Q=2.1428


0.1

1

10

100

1.8 1.9 2 2.1 2.2 2.3 2.4

Ana

lyze

d C

urre

nt [

pA]


37K

19+

37K

18+

37K

17+

37K

16+

H2+

15N

7+

13C

6+

16O

7+

14N

6+

12C

6+

40A

r17+

40A

r18+


EBIT CB

RFQ

CM2

CM3 (2014)

CM1SECAR




A1900

15N7+, A/Q=2.142813C6+, A/Q=2.1667


0.1

1

10

100

1.8 1.9 2 2.1 2.2 2.3 2.4

Ana

lyze

d C

urre

nt [

pA]


37K

19+

37K

18+

37K

17+

37K

16+

H2+

15N

7+

13C

6+

16O

7+

14N

6+

12C

6+

40A

r17+

40A

r18+

37Cl

Ene

rgy

Loss

[A

.U.]

Radioactive Ion Beam Measured In The ANASENIonization Chamber

37Cl

37K

Ene

rgy

Loss

[A

.U.]

Contaminant beams in same setting as 37K17+

Reaccelerated 37K RIB

Cl

13C

Energy [A.U.]

Ene

rgy

Loss

[

Cl

13C

Energy [A.U.]E

nerg

y Lo

ss [

First radioactive ion beam delivery to user 8/20/2013!

Summary

• ReA is the first post-accelerator coupled to a fragmentation facility

• The EBIT charge breeder provides high purity beams

• The SC cavities perform above specification and have been operated reliably since 2010

• Commissioning and final installations are progressing well, RIB • Commissioning and final installations are progressing well, RIB beams below or close to the Coulomb barrier(light ions) will available for users in 2014

• The first radioactive ion beam was delivered to users in August of 2013

• ReA will serve as post accelerator for FRIB

Co-authors

D. Leitner1,2, D. Alt2, T. M.Baumann2, C. Benatti2, B. Durickovich1, K. Kittimanapun2, A. Lapierre2, L. Ling-Ying, S. Krause2, F. Montes2, D. Morrissey2, S. Nash2, R. Rencsok2, A. Rodriguez1, C. Sumithrarachchi2, S. Steiner2, S. Schwarz2, M. Syphers2, S. Williams2, W. Wittmer1, X. Wu1

1Facility for Rare Isotope Beams, Michigan State University,

, Slide 30

1Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 USA2National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, USA

status of the rare isotope reaccelerator facility reaepaper.kek.jp/pac2013/talks/fryba2_talk.pdf ·...

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