isla, a recoil separator for rea3/6/9/12iwasaki/rea6/slides/5-isla_amthor.pdf•writing workshop in...

ISLA, A Recoil Separator for ReA3/6/9/12M AT T A M T HORBUCK N ELL UN I VERS I T Y

ReA3 Upgrade Workshop20 August 2015

Outline• The context: FRIB and ReA• Expected beams

• ISLA coupling to ReA

• ISLA• Description

• Physics case by Re-accelerated Energy

• Status update and outlook

220 August 2015 A.M. AMTHOR - REA UPGRADE WORKSHOP

Context

20 August 2015 A.M. AMTHOR - REA UPGRADE WORKSHOP 3

FRIB beamsUranium

Fragmentation & FissionFast & Reaccelerated

Fusion-Evap., MNT/Deep-Inel.Reaccelerated Only

FRIB will enable the production and study of a large fraction of the bound isotopes expected to exist but not yet observed (especially below Z=92).

FRIB will uniquely couple a fragmentation/fission RIB production facility with a reaccelerator.

Reactions with reaccelerated FRIB beams will provide a novel reach into isotopes of heavy elements.


B. Sherrill

Status of ReAthe Re-accelerator at NSCL

EBIT CB

RFQ

CM2

CM3 (2014)

CM1

ReA3

ReA6(proposed)

SECAR (Proposed)

AT-TPC

ReA6/12 Equipment and Beamlines TBD

D-LineN4 Stopped beamsA1900

L-Line

General Purpose Line

2010/10: RFQ commissioning started

2011/04: CM1 first beam acceleration

2011/06: CM2 first beam acceleration

2012/04: first 1+-n+ acceleration

2013/06: Experimental hall beam line

2013/08: First rare isotope experiment

2014/05: Cryomodule 3 installation

ReA3 now complete!

Space for ReA12

cryomodules

520 August 2015 A.M. AMTHOR - REA UPGRADE WORKSHOP Slide: G. Bollen

ISLA footprint

ISLA would occupy existing vault space in the NSCL that is to be reconfigured as the ReA12 experimental vault.

Incoming beam swinger—currently not shown—will fit in available space.


Drawings: D. Lawton

ISLA


What is ISLA•Isochronous spectrometer with large acceptance, based on the TOFI design at LANL but with much larger acceptance, for ReA12 beams.

•The selected design of the working group (July 2014)

•High M/Q resolving power, R > 1000(symmetry reduces aberrations)

•Large acceptance• 64 msr

• +/- 10% momentum

•Flexible M/Q spectrometer• Small focal plane (implantation & decay)

• Space about target for GRETA

• Incoming beam swinger allows operation off zero degrees (up to 50 degrees)

• First half could be used in a VAMOS-like mode or to reject beam by Bρ

• Could be operated in gas-filled mode

• Low energy RF kicker to allow physical separation of products by M/Q


M/Q separationIn Time-of-Flight at the end of ISLA

• 100Sn simulation

• Monte Carlo in LISE++

• Assumes 1 ns width

• Assumes flexible bunchspacing from Q-breeder(under development)

Addition of a low-energy RF kicker could provide spatial separation


ISLA with RF kicker100kV across 10 cm gap over 20 cm length

Use some harmonic of ReA12 RF – 80 MHz

• Attempt to align multiple charge states of the residual of interest (at least two should always be possible)

• Attempt to deflect strongly populated contaminants

9th harmonic for 100Sn production aligns 3 most intense q-states

100Sn purity = 1.4x10-3

(factor of 35 improvement)


Physics case overview• Precise measurements of electromagnetic transitions.

• Transfer studies of shell evolution, pairing and n-n correlations.

• Astrophysical processes: r, rp, νp, cosmochronometers, etc.

• Multi-nucleon transfer with FRIB beams to n-rich SHEs to work toward the island of stable heavy elements.

• Fusion evaporation with FRIB beams, esp. to n-deficient species (p- and 2p-radioactivity)

• And more… including a majority of the NSAC RIB taskforce benchmarks

ReA12 with FRIB beams makes these studies possible, but only if we have a flexible spectrometer to remove unreacted beam and identify the products. ISLA can meet these needs.

*Selected cases


Recoil Separator Needs → ISLA• Space about the target for detection, targets, swinger, etc.

• Achromatic image (small FP) for implantation → decay

• Bρmax = 2.5 Tm (for gas-filled mode)

• Eρmax = 105 MV (median 42 MV)

• Swinger for incoming beam angles up to 5o degrees

• M/Q resolving power up to 1000 (most 100-400)

• Q and Bρ acceptance +/-10% (larger helps for some)

• Angular Acceptance +/-170 mrad (most +/- 10-110 mrad)

• Physical M/Q separation: one yes (most no or don’t specify)

• Bunch size/spacing: 200ps/80ns (most don’t specify)


Physics Cases Auxiliary Systems NeededTarget area

◦ GRET(IN)A, CAESAR, SuN, HAGRiD

◦ ORRUBA

◦ Plunger

◦ LENDA, VANDLE

◦ Gas jet target

Focal plane◦ TOF, dE, TKE, (tracking)

◦ Implantation decay, multiple channels: α, β, γ, n, fission.


A diverse physics casefrom diverse approaches


Fig: W. Mittig

ISLA Physics Case by ReA Energy


ISLA Physics – ReA3Note: Some programs span energy ranges (see “some” and “more”)

Some Astrophysical reaction rate studies for nucleosynthesis and explosive burning (some not well suited to SECAR)

• (p,g) for A > 40 where accepting many Q helps rel. to SECAR

• (a,p) large angular acceptance helps rel. to SECAR

• (d,n) to study hydrogen burning rates up to A = 40

Some Fusion evaporation

• Excited states in exotic proton-rich nuclei (e.g. 100Sn region)

• Superheavy element synthesis and fusion dynamics


ISLA Physics – ReA6More Astrophysics

• Heavy element nucleosynthesis, A > 50

More Fusion

• Super-heavy element synthesis and studies

• Heavy ion fusion dynamics

• Cross-shell excitations in n-rich p isotopes

Inelastic and Transfer

• Precise EM transitions in light nuclei, using e.g. (d,p) or (p,p’)

Transfer

• Synthesis of elements in core-collapse SN, νp-process, (p,n)

• some nn-correlations toward dripline

Deep Inelastic / Multi-Nucleon Transfer

• Collectivity in exotic nuclei with gamma spectroscopy of level lifetimes e.g. 80Ge at 8MeV/u

• Production and properties of heavy n-rich nuclei (standard kinematics)


ISLA Physics – ReA9More Transfer

• More nn-correlations toward the dripline

More Multi-Nucleon Transfer

• Production and properties of heavy n-rich nuclei (inverse kinematics)


ISLA Physics – ReA12More Transfer

• (d,p) surrogate reactions for stewardship science up to 12 MeV/u for uranium

• Tracking shell evolution with high-l intruder states

More Coulomb excitation

• Collectivity in exotic nuclei with gamma spectroscopy of level lifetimes e.g. 132Sn at 20MeV/u

More Multi-nucleon transfer

• r-process endpoint and decay studies, near N=126


Status & Outlook


Progress and status(since last LEC meeting in 2013)• Physics case for a recoil separator formulated • Community interest questionnaires collected (Winter – Spring 2014)

• Text, figures, references for whitepaper collected (Summer 2014)

• Comparison of proposed systems and selection based on the needs of the physics cases• Writing workshop in June 2014 – recommended ISLA

• Separate working group meeting in July 2014 – selected ISLA

• NSAC Long Range Plan Town Hall Meeting in August 2014• ISLA whitepaper released before the Meeting

• Full ReA12 Upgrade included as explicit recommendation

• Updated whitepaper published in hardcopy in Spring 2015

• SBIR grant to develop and evaluate models of novel dipole designs for ISLA – work completed July 2015

• More funding is needed to move from conceptual design to complete a true preliminary design of ISLA.


More information - outlook•Budget: M$10.0• Past experience

• 20%-25% contingency

• Swinger, RF kicker, cryogenic lines, basicdetection

• Assumes cryogenic capacity exists

•See the whitepaper for more detail on the physics case and design (linked from lecmeeting.org).

•Large community interest• Well subscribed workshops

• 18 physics case proposals involving 15 distinct institutions (majority of RISAC benchmarks)

•Next• Refine designs of swinger, low energy RF kicker, large gap dipoles

• Developments in ReA time structure to allow clear time of flight M/Q identification

Start funding in FY 2016 to start ISLA with early FRIB completion


Summary

ISLA, coupled with a fully upgraded ReA12 and existing and planned detector systems, is necessary to realize the full promise of the world leading scientific capabilities of FRIB.


• ISLA• Meets all the needs of the physics case proposed for a ReA12 recoil separator

• Rejects unreacted beam and provides high mass resolving power in ToF

• Addresses a majority of he RISAC Benchmarks, coupled to FRIB/ReA12 etc.

• Strong science case has been presented and working group participation has been strong

• Funding is needed within FY2016 to continue the design process to ensure completion of ISLA for FRIB start.

• ReA Upgrade is essential to the physics mission of ISLA.• Very little of the ISLA physics case is possible with only ReA3

• Key benchmarks require the full ReA12 energy upgrade (unique)• stewardship science

• r-process nucleosynthesis

AcknowledgementsDaniel Bazin for ISLA concept, designs, simulations.

Fellow working group conveners: Wolfgang Mittig and Jerry Nolen

Past conveners: Darek Seweryniak and Kenneth Gregorich

Contributors to the discussions and whitepaper:


Dieter AckermannTan AhnDaniel BazinSaul Beceiro NovoGeorg BergMustapha BrahimChris CampbellRichard CastenKelly ChippsShailendra ChouhanJolie CizewskiLorenzo CorradiManoel CouderAlfredo EstradeAlexandra GadeJacklyn GatesKenneth Gregorich

Sophie HeinzChristine HamptonCalem HoffmanHironori IwasakiRitu KanungoZach KohleyDon LawtonC. J. ListerWalter LovelandLibby McCutchanFernando MontesWitold NazarewiczFilomena NunesOmar NusairGeorgios PerdikakisMauricio PortilloMaurycy Rejmund

Andrew RogersChristelle SchmittDariusz SeweryniakArtemis SpyrouSuzana SzilnerSamuel TaborOleg TarasovAditya WakhleScott Williams

Invitation

Join us by contributing to the definition of the science case for ISLA!


isla, a recoil separator for rea3/6/9/12iwasaki/rea6/slides/5-isla_amthor.pdf•writing workshop in...

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