The new vacuum mode separator at JyväskyläJ. Uusitalo, J. Sarén, M. Leino

RITU and γ-groups

University of Jyväskylä, Department of Physics

UK, Daresbury, Liverpool, Manchester, York

JUROGAM

RITU

GREAT

TDR

IReS target chamber

SACRED

Köln plunger

LISA

University of

Liverpool

SAGE

energy focus

angular focus

mass focus

Configuration – QQQEDMD

Central trajectory length 5.62 m

Quadrupoles: eff. length 35 cm, full aperture 10 cm

Magnetic dipole: rad. of bend 1 m, defl. angle 35 deg., gap 10 cm, max. field 1 T

Electric dipole: rad. of bend 4 m, defl. angle 10 deg., gap 12 cm, max. field ± 150 kV

Separator plan for Bratislava (A. P. Popeko)

Bratislava separator

Angular focus in x- and y-directions

Energy focus and mass dispersion in x-direction

 Magnetic rigidity:

Electric rigidity:  Resolving power: 

Deflection angles in electric field:

Universal features:

- Both electric and dipole fields are needed - Beam is dumped inside the first dipole (chamber)- Mass resolving power about 350 FWHM can be reached (with 2 mm beam spot size)- Full energy beam suppression factor of 109-1015 can be expected

Charged particle in electric and magnetic fields

q

Tm

q

mvB

2

q

T

q

pvE

2

xxx

xR

|2

|

00

pp

ERER

p

ER

qA

qA

DRS: Q1-Q2-Q3-WF1-WF2-Q4-Q5-Q6-S1-S2-MD1-Q7-Q8-Q9 (13.0 m)

CARP: Q1-MD1-H1-H2-ED1-H3-Q2CAMEL: Q1-Q2-ED1-S1-MD1-S2-ED2HIRA: Q1-Q2-ED1-M1-MD1-ED2-Q3-Q4 (8.6 m)

JAERI-RMS: Q1-Q2-ED1-MD1-ED2-Q3-Q4-O1 (9.4 m)FMA: Q1-Q2-ED1-MD1-ED2-Q3-Q4 (8.2 m)EMMA: Q1-Q2-ED1-MD1-ED2-Q3-Q4 (9.04 m)JYFL new: Q1-Q2-Q3-ED1-MD1 (6.84 m)

Q quadrupole S sextupoleH hexapoleM multipoleO octupoleWF velocity filterED electric dipoleMD magnetic dipole 

Mass separators all around the world: some trends

- Maximizing angular, mass and energy acceptance while minimizing geometric and chromatic aberrations.

- The largest aberrations are (x|δ2), (x|θδ) and (x|θ2). These are minimized by adding a curvature to the magnetic dipole entrance and exit.

- Higher order aberrations found to be negligible.

Design principles and aberrations

Optical layout in floor coordinates

Reference particle: A = 100, Q = 26, E = 100 MeV

Angular focus in x- and y-directions

X-direction, 5 angles: 0, ±15 and ±30 mrad

Y-direction, 5 angles: 0, ±20 and ±40 mrad

Energy focus and mass dispersion in x-direction

Energy deviation: 0, ±3.5 and 7.0 %

Angles: 0 and ±30 mrad,Masses: 100 and ± 1 %Energies: 100 and ± 7.0 %

3 different energies 3 different angles 3 different masses

Main properties of the new JYFL separator compared to EMMA @ TRIUMF

EMMA JYFL new

Length from target to focal plane (m) 9.04 6.84

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Dipoles MD ED1, ED2 MD ED

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Radius of curvature (m) 1.0 5.0 1.0 4.0

Deflection angle (o) 40 20 40 20

Effective field boundary inclination angles (o) 8.3 0 8.0 0

Effective field boundary radii (m) 3.472 - 2.800 -

Gap (cm) 12 12.5 10 14

Maximum field 1.0 T 50 kV/cm 1.0 T 42 kV/cm

Maximum rigidity 1.0 Tm 25 MV 1.0 Tm 17 MV

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Magnetic lenses Q1 Q2, Q3 Q4 Q1 Q2, Q3

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Bore diameter (cm) 7 15 20 10 15

Effective length (cm) 14 30 40 25 35

Maximum pole tip field (T) 1.21 0.87 0.81 0.5 0.75

Maximum field gradient (T/m) 35 12 8.1 10 10

Main properties of the new JYFL separator compared to FMA @ ANL

FMA JYFL new

Length from target to focal plane (m) 8.20 6.84

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Dipoles MD ED1, ED2 MD ED

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Radius of curvature (m) 1.0 4.0 1.0 4.0

Deflection angle (o) 40 20 40 20

Effective field boundary inclination angles (o) 7.0 0 8.0 0

Effective field boundary radii (m) 2.8 - 2.8 -

Gap (cm) 12 10 10 14

Maximum field 1.1 T 50 kV/cm 1.0 T 42 kV/cm

Maximum rigidity 1.1 Tm 20 MV 1.0 Tm 17 MV

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Magnetic lenses Q1 Q2 Q3, Q4 Q1 Q2, Q3

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Bore diameter (cm) 10 10 20 10 15

Effective length (cm) 30 20 30 25 35

Maximum pole tip field (T) 0.8 0.8 0.8 0.5 0.75

Maximum field gradient (T/m) 16 16 10.7 10 10

EMMA JYFL new

- Configuration QQEDMDEDQQ QQQEDMD- Horizontal magnification -2.08 -1.55- Vertical magnification 1.33 -4.48- M/Q dispersion 10.0 mm/% (variable) 8.1 mm/%- First order resolving power, 240 259 2 mm beam spot - Solid angle acceptance 16 msr 10 msr central m/q and energy- Energy acceptance for central mass and angle +25 % - 17 % +20 % - 15 %- M/Q acceptance 4 % 7 %

Main properties of the new JYFL separator compared to EMMA @ TRIUMF

FMA JYFL new

- Configuration QQEDMDEDQQ QQQEDMD- Horizontal magnification -1.93 -1.55- Vertical magnification 0.98 -4.48- M/Q dispersion 10.0 mm/% (variable) 8.1 mm/%- First order resolving power, 259 259 2 mm beam spot - Solid angle acceptance 8 msr 10 msr central m/q and energy- Energy acceptance for central mass and angle +20 % - 15 % +20 % - 15 %- M/Q acceptance 4 % 7 %

Main properties of the new JYFL separator compared to FMA @ ANL

Properties of the new JYFL separator compared to the planned Bratislava separator

Bratislava JYFL new

- Configuration QQQEDMD QQQEDMD- Horizontal magnification -1.0 -1.56- Vertical magnification -4.42 -4.48- M/Q dispersion 6.0 mm/% 8.1 mm/%- First order resolving power, 300 259 2 mm beam spot - Solid angle acceptance 3.6 msr 10 msr central m/q and energy- Energy acceptance for central mass and angle +25 % - 20 % +20 % - 15 %- M/Q acceptance 4 % 7 % TOF needed to obtain

mass res. power

What kind of research work can be done were RITU separator is not feasible

Probing the N Z line up to 112Ba

- decay spectroscopy (proton and -particle decay) at the 100Sn region- proton drip-line spectroscopy

o competition between proton and gamma decayo new proton emitters

- rp-processo masses, half-lives and isomers in N=Z nuclei determine the rp- process synthesis rate

- proton-neutron pairing interaction with T = 0 and T = 1- mirror nuclei

o effects of increasing Coulomb fieldo study of isospin symmetry breakingo proton skins (N < Z nuclei)

- super-deformation and hyper-deformation (N Z 40)

Methods

- focal plane detector system:

o DSSSD and PSAC (1 mm granularity)

- Tracking

o PSAC and IC

- A and Z- identification

o tape system

o planar-Ge and clover Ge

- focal plane spectroscopy

       - , proton, , , -delayed protons and alphas

       - prompt and delayed coincidences

- in-beam spectroscopy tagging with focal plane measures

- Recoil beta tagging (RBT), betas, beta-delayed protons

- Recoil decay tagging (RDT), protons, alphas

- Recoil delayed gamma tagging

JIonO – IonOptical simulations, Jan Sarén Features (some are not implemented yet):

• both graphical and text interfaces

• uses GICO/GIOS transfer matrices

• adjustable aperture slits

• export/import data

• real particle parameters as input data (m, E, q)

• Multiple types of plots

• Windows and Linux

Phase space correction

Tracking particles: Energy, TOF, x and y positions (angles)

Mass separation at focal plane

X-deviations versus TOF can be seen in phase space corrected data -> time correction can be made to improve x-resolution

Bratislava separator

TOF (1 m) vs focal plane position.

Masses 99, 100, 101 with

charge states 25, 26, 27

Energy 100(7) MeV

σx = ± 30 mrad, σy = ± 30 mrad

Simulation of electric field in deflector (code Poisson Superfish)

- gap 14 cm- rounded edges- splitted anode- maximum voltage between plates is about 0.6 MV

- 3-dim. analysis under work (COMSOL multiphysics)

Simulating particle trajectories in deflector field

Simple modified Euler equation is used to trace particles in electric field.

Real transfer matrix coefficients can be obtained from these simulations. This more realistic matrix can be used in optical simulations of the new separator.

100 MeV, 100 u, 26 e

200 MeV, 50 u, 21 e

92Mo: 362 MeV, 92 u, 32 e

147Tm: 222 MeV, 147 u, 37 e

40Ca + 40Ca → 80Zr* → 78Zr + 2n

Elab = 110 MeV (MOT)

Target 400 μg/cm2

M = 78, Q = 18, 19, 20, E = 46(6) MeV, (2n, pn, 2p), 15 %

M = 77, Q = 18, 19, 20, E = 46(6) MeV, (3p, 2pn), 72 %

M = 75, Q = 17, 18, 19, E = 44(6) MeV, (αn), 3 %

M = 74, Q = 17, 18, 19, E = 44(6) MeV, (α2n), 10 %

σx,y = ± 35 mrad

48Ca + 208Pb → 256No* → 254No + 2n

Elab = 215 MeV (MOT)

Target 400 μg/cm2

M = 254, Q = 17, 18, 19, E = 35(5) MeV, σx,y = ± 50 mrad

High acceptance mode

Quadrupole polarities inversed

solid angle acceptance 10 msr → 14 msr

1st order resolving power 259 → 155

d(132Sn,p)133Sn @ 6 MeV/n

100 μg/cm2 (CD2)n target

Beam energy spread ± 0.17 %

Recoil energy spread ± 0.23 % (± 2.5 %)

In coincidence with protons emitted between 120o and 180o in the lab

Rigidities too high

8.8 μm Au foil to slow down the products

→ angular spread σ = 22 mrad, Energy spread less than 1 %

Final input: Uniform distributions

Beam spot size x,y = ± 0.5 mm

Beam: E = 325(3) MeV, σx = ± 35 mrad, σy = ± 52 mrad

Recoils: E = 322(3) MeV, σx = ± 35 mrad, σy = ± 52 mrad

colors coded as:

blue: 132Sn beamred: 133Sn (all fragment angles)green: 133Sn (coincidence with fragment

lab. angles 120 – 180 deg.)magenta: 133Sb fusion productlight blue: 133Sb via d,n transfer

EMMA versus JYFL new

Input:

x, y: ± 1.5 mmx´, y´: ± 20 mradEnergy is as they come from reactions

colors coded as:

blue: 132Sn beamred: 133Sn (all fragment angles)green: 133Sn (coincidence with fragment

lab. angles 120 – 180 deg.)magenta: 133Sb fusion productlight blue: 133Sb via d,n transfer

EMMA versus JYFL new

Input:

x, y: ± 1.5 mmx´, y´: ± 20 mradEnergy is as they come from reactions

Input:

x, y: ± 1.5 mmx´, y´: ± 20 mradEnergy is as they come from reactions

colors coded as:

blue: 132Sn beamred: 133Sn (all fragment angles)green: 133Sn (coincidence with fragment

lab. angles 120 – 180 deg.)magenta: 133Sb fusion productlight blue: 133Sb via d,n transfer

EMMA versus JYFL new

54Fe + 58Ni → 112Xe → 110Xe + 2n @ 195 MeV, B. Cederwall et. al.,

Comparison between the gas-filled recoil separator RITU

and the new vacuum mode separator

With 5 pnA 54Fe beam the rates

using the gas-filled recoil separator RITU are:

JUROGAM ~ 100 kHz

Focal plane silicon rate ~ 5 kHz

using the vacuum-mode separator are:

JUROGAM ~ 100 kHz

- about 50 % less transmission, 3 charge states

Focal plane silicon rate ~ 2.5 kHz

- using mass slits, 3 charge states and mass 110 (106)

Focal plane silicon rate ~ 1.0 kHz

→

20 pnA beam will give

JUROGAM ~ 400 kHz

Focal plane silicon rate ~ 4.0 kHz

and 100 % more yield for 110Xe

when compared to RITU

Should be valid for all cases for A < 110

if correlation technique is needed for

final identification and/or tagging

Weak evaporation channels 2n, 3n, ... pn, p2n …