Canada’s National Laboratory for Particle and Nuclear Physics Laboratoire national canadien pour la recherche en physique nucléaire

et en physique des particules

Owned and operated as a joint venture by a consortium of Canadian universities via a contribution through the National Research Council Canada

Propriété d’un consortium d’universités canadiennes, géré en co-entreprise à partir d’une contribution administrée par le Conseil national de recherches Canada

Precision mass measurements for

nuclear physics

J. Dilling

TRIUMF is owned & operated by a consortium of 19 universities

Founded 45 years ago in Vancouver

Members University of Alberta

University of BC

Carleton University

University of Guelph

University of Manitoba

Université de Montréal

Queen’s University

Simon Fraser

University of Toronto

University of Victoria

York University

Canada’s National Laboratory for

Particle and Nuclear Physics

Associate Members University of Calgary

McMaster University

University of Northern BC

University of Regina

Saint Mary’s University

University of Winnipeg

McGill University

Western University

ISAC

Highest Power ISOL RIB

facility

- Nuclear Structure

- Nuclear Astrophysics

- Fund. Symmetries

- CMMS (bNMR)

Nordion

commercial medical

isotope production

3 cyclotrons

CMMS

Centre for Molecular and

Material Science (mSR)

Particle Physics

Pienu (- 2012)

Ultra Cold Neutrons (2015 -)

Cyclotron

500 MeV

350 mA

ISAC-I

60 keV,

1.7 AMeV

ISAC-II

>10 AMeV 40 MV SRF

Heavy Ion Linac

Advanced Rare

Isotope Laboratory

(ARIEL)

e-LINAC

300-500 kW

photo-fission

driver

(2015-2017)

ISOL facility with highest primary

beam intensity (100 mA, 500 MeV, p)

Programs in

• Nuclear Structure & Dynamics

• Nuclear Astrophysics

• Electroweak Interaction Studies

• Material Science

ISAC I:

60 keV & 1.7 AMeV

ISAC II:

10 AMeV for A<150

16AMeV for A<30

DESCANT GRIFFIN

expand RIB program with:

• 3 simultaneous beams

• increased number of

hours delivered per year

• new beam species

• enable long beam times

(nucl. astro, fund. symm.)

• increased beam

development capabilities

New electron linac driver

for photo-fission

New proton beamline

staged installation

started 2012

Cyclotron Vault (exiting)

RIB front end

Electron Hall

Target Hall

October 1st:

22.9 MeV e-beam

ARIEL, Civil construction and eLINAC

ARIEL: e-linac for photo-fission total power: 0.5 MW

Photo-fission products using 50 MeV 10 mA electrons on Hg convertor & UCx target.

up to 1014 fissions/s

100 kW, 25 MeV electrons by 2014 500 kW, 50 MeV electrons by 2017

TIMELINE:

• 2014 first beam, target R&D

• 2017 new front end (phase II)

• 2017 physics production 8Li

• 2018 photo fission

• 2020 proton beam (3 beams)

Mass difference of 2 nuclei

gives energy gain in

reactions (like in stars)

and for beta decay

Halos and skins

Element Synthesis

via r-process (supernova)

Evolution of

Nuclear Shells

dm/m = 10-7

10-7< dm/m < 10-6

dm/m < 10-8

10-6< dm/m < 10-5

Abundance vs. A

Binding energy includes

all effective interactions

and reflects the nuclear potential

The nature of neutrinos

and double beta decay

Kepler's supernova

remnant, SN 1604

500 MeV

protons

Mass

Separator

Low-energy beam

transport

TITAN

Programs in

• Nuclear structure &

dynamics

• Nuclear astrophysics

• Electroweak interaction

Studies

• Material science

ISOL facility with highest primary beam

intensity (100 mA, 500 MeV p)

TRIUMF’s Ion Trap for

Atomic and Nuclear

Science

• High-precision mass

measurements

• In-trap decay

spectroscopy

J. Dilling et al., NIMB 204 (2003) 492

RFQ: Accumulation,

cooling, and

bunching

EBIT: ms charge breeding

BNG: fast m/q

selection

MPET: mass

measurement via

cyclotron frequency

determination

Future traps: • MR-TOF MS after RFQ (w/ U. of Giessen)

• Cooler Penning trap before MPET

• Both set-ups installed off-line

z0

r0

ring

electrode

end cap

ions

M. Brodeur et al., PRC 80 (2009) 024314; M. Brodeur et al., IJMS 20 (2012) 310

3.7 T magnet

2pnc = (q/m) B

-100 -50 0 50 100

56

58

60

62

64

Mean T

ime o

f F

light [m

s]

nRF

- 1831558 [Hz]

31Na+

T1/2 = 17 ms

n+ + n- = nc

• Lorentz steerers

• TOF-ICR technique

Fast measurements:

T1/2 ≥ 9 ms (11Li)

Since PT were

developed for ions,

they behave

the same way for

stable or unstable

particles!

Ideal for systematic

test and

optimizations

K. Blaum, J.Dilling,

W. Nörtershäuser,

Phy. Scr. T152 (2013)

K. Blaum et al., EPJ A 15, 245 (2002)

ISOLTRAP: Carbon Cluster tests

(dm/m)res = 8·10-9

B. Brodeur et al., INJM 310, 20 (2012)

TITAN: Global compensation method

ΔR/Rtotal = − 4(6) × 10−12 · Δ(m/q) · V0

V.-V. Elomaa et al., NIM A 612, 97 (2009)

JYFLTRAP: Carbon Cluster tests

σres,lim(r)/r=7.9×10-9

C. Droese et al., NIM A 632, 157 (2011)

SHIPTRAP: Temperature stability

σo=1.3(3)×10−9/h

Reached high accuracy

and precision:

Excellent reliability Other on-line trap systems do this

as well…CPT, LEBIT…

n

NBqTm

RFc

11

ndB

m

qc

pn

2

1

-4

-2

76Rb+12

Demonstrated off-line that 5 ms cycle are possible:

A. Chauduri et al., Applied Physics B (2014) 114, 99

Mg (p-rich, light)

Island of Inversion

• N-deficient Mg isotopes

• N-rich Na, Al, Mg isotopes (IoI)

Mass measurements at A=20,21

• Mass measurements of Mg masses

Technical difficulty: ISOL production is not selective:

• isobars are co-produced with the isotopes of interest!

• Na, closer to stability, and longer-lived

• much more extracted and delivered to

experiment (1.000.000-1 ratio)

• cleaning system required!

Tricks for clean beams:

Go to the source! Ion Guide Laser Ion Source (IG-LIS)

• Suppress normal surface ions (Na).

• Only allow neutral atoms to drift into the laser-ionization region

• Selective ionization of species (Mg)

• Laser ion source still has significant contribution of

surface ions

Performance of the source: IG-LIS

Background reduction of 6 orders of magnitude!

Mg-isotopes

Penning trap mass measurements

M(A,T,Tz) = a(A,T) + b(A,T) Tz + c(A,T) Tz2

• G.S. binding energy

• non-zero d coefficients in all three

multiplets, A=20,0+, A=21,1/2+, 5/2+

• dexp cannot be explained by

USDA/B models

• uncertainties in cEFT calculations

too large to be definitive

20Mg+

20Mg: 45s deviation from

AME12 & 15x improved

precision

21Mg: 14s 22x

improved precision

Compared to USDA/B &

cEFT NN+3N predictions

Excellent collaboration of target/ion source group, experiment and theory

Mass measurements with TITAN:

• Fast (short half-lives !)

• Precise

• Accurate

Island-of-Inversion Mass Cartography

figure from Himpe et al, PLB 658 (2008) 203

•Many with very short T1/2:

• 32Na: 12.9 ms

• 31Na: 17 ms

• 34Mg: 20 ms

2.3s crossover at N = 21:

• Island-of-inversion behavior?

• Isomer?

1Rotaru et al. PRL 109 (2012) 092503

A. Chaudhuri et al, PRC 88 (2013) 054317; A.Kwiatkowski et al, submitted to PLB;

Dn(N

,Z)

=S

2n(N

+2

,Z)

- S

2n(N

,Z)

Proton Number Z

Dn(N=20) falls off in the island of

inversion.

Dn(32Mg) lowest of any magic

number

2.3s crossover at N = 21:

• Island-of-inversion behavior?

• Isomer?

• Island-of-inversion behavior due to

correlation energy

• Isomer would have a smaller effect

• Decay losses excluded 26 ms

state1

J. Dilling et al., NIMB 204 (2003) 492

RFQ: Accumulation,

cooling, and

bunching

EBIT: ms charge breeding

BNG: fast m/q

selection

MPET: mass

measurement via

cyclotron frequency

determination

• Superconducting magnet, Helmholtz configuration

• Design specs up to an electron beam 70 keV & 5 A

• 7 radial ports with recessed Be windows

A. Lapierre et al., NIMA 624 (2010) 54

Sikler lens

cathode

electron gun

500 mA achieved

dm m

m q B TRF N≈

74Rb8+ T1/2 = 64 ms

Heaviest superallowed b emitter

~1/TRF

N limited by yield/beam time

TRF limited by T1/2

B limited by dB/B

q up to Z+

Boost precision

or

Reduce experimental requirements

for the same precision

S. Ettenauer et al., PRL 107 (2011) 272501

A.T. Gallant et al., PRC 85 (2012) 044311

78Rb8+

TRF = 197 ms

isomer g.s.

To measure 71Ge Q-value, needed

to separate small amount of 71Ge

from overwhelming 71Ga

contamination

Exploited Z dependence of charge-

state distribution & large increase in

Ie at closed shells

Ne-like ions could be achieved for Ee

~ 2 keV & Jt ≥ 20 A cm-2 s

predominantly 71Ga21+ and 71Ge22+

(CBSIM simulations allow for a

systematic approach)

A.A. Kwiatkowski, T.D. Macdonald, et al., NIMB 317 (2013 517

M.C. Simon et al., RSI 83 (2012) 02A912, D. Frekers, M.C. Simon, et al., PLB 722 (2013) 233

electron beam

70 mA / 2.0 kV

Me

an

TO

F [m

s]

nRF – 16 821 000 [Hz]

Laser: OFF ON

Q = 21+ 71Ga 71Ga, 71Ge

Q = 22+ – 71Ge

n

s

D. Frekers et al., PLB 706 (2011) 134; D. Frekers, et al., PLB 722 (2013) 233; T.D. Macdonald, et al, PRC 89 (2014) 044318

Confirmation of 71Ga and 51Cr nuclear structure.

The discrepancy persists.

g

444

244

1263

2235

z 30Mg 315(5) ms

30Al 3.6 s

z 30Si

T.A. Hinners et al, PRC 77 (2008) 034305; D.E. Alburger & D.R. Goosman, PRC 9 (1974) 2236

Time of Flight [ms]

ion

s/s

hot

keV

co

un

ts

tCB = 500 ms

tBG = 300 ms

tCB = 50 ms

-150 -100 -50 0 50 100 150

21

22

23

24

Me

an

Tim

e o

f F

ligh

t [m

s]

nRF

- 15 154 066 [Hz]

30Mg8+ tCB = 50 ms

A.A. Kwiatkowski, R. Klawitter, A. Lennarz, et al, in preparation

Preliminary

Time of Flight [ms]

ion

s/s

hot

-100 -50 0 50 10018.8

19.2

19.6

Me

an

Tim

e o

f F

ligh

t [m

s]

nRF

- 20 843 189 [Hz]

30Al11+ tCB = 4 s keV

co

un

ts

tCB = 500 ms

tBG = 300 ms

tCB = 4 s

A.A. Kwiatkowski, R. Klawitter, A. Lennarz, et al, in preparation

Preliminary

n

D. Frekers et al., CJP 85(2007)57; K.G. Leach et al., arXiV 1405.7209

A. Lennarz, et al, Phys. Rev. Lett. 113 (2014) 082502; K.G. Leach et al., arXiV 1405.7209

0-2 s 6-8 s 12-14 s 18-20 s

• RFQ space-charge limit 10.000× smaller

than EBIT

• Inject multiple ion bunches :

• Open trap for singly charged ions

• Close trap for singly charged ions (DV)

• After charge breeding, ions experience

deep potential well (DV∙Q)

K.G. Leach et al., arXiV 1411.4083

RFQ accumulation,

cooling, & bunching

SCI

SCI

HCI

offline

ion source

BNG fast m/q selection

EBIT ms charge breeding &

in-trap decay spectroscopy

MPET high-precision

mass measurement

Multi-Reflection Time-of-Flight Mass Separator: - Tested in Giessen to M/DM ≈ 50 000

- Will improve beam-purity capability from 1:200 to 1:104 desired ion to contamination ratio

- Arrived at TRIUMF 10th of September

- Off-line commissioning Spring 2015, on-line December 2015

Owned and operated as a joint venture by a consortium of Canadian universities via a contribution through the National Research Council Canada

Propriété d’un consortium d’universités canadiennes, géré en co-entreprise à partir d’une contribution administrée par le Conseil national de recherches Canada

Canada’s National Laboratory for Particle and Nuclear Physics Laboratoire national canadien pour la recherche en physique nucléaire

et en physique des particules

TRIUMF:

Alberta | British Columbia | Calgary |

Carleton | Guelph | Manitoba | McMaster |

Montréal | Northern British Columbia |

Queen’s | Regina | Saint Mary’s Simon

Fraser | Toronto | Victoria | Winnipeg | York

TIT

AN

gro

up @

IS

AC

C. Andreoiu, M. Alansarri, J.C. Bale, B.R. Barquest, U. Chowdhury,

A. Finlay, D. Frekers, A.T. Gallant, G. Gwinner, R. Klawitter, B.A.

Kootte, A.Kwiatkowski, D. Lascar, K.G. Leach, A. Lennarz,

E. Leistenschneider, A. Mayer, D.A. Short, J. Dilling

and the TITAN Collaboration