Design and Development of a Trochoidal Mass Separator at the Berkeley Gas-filled Separator J.M. Gates, K.E. Gregorich, G.K. Pang, N.E. Esker and H. Nitsche Lawrence Berkeley National Laboratory 11 th International Conference on Nucleus-Nucleus Collisions May 29, 2012 San Antonio, TX

Outline Region of Interest Berkeley Gas-filled Separator Trochoidal Mass Separator

ms ms ms s s ms  s ms s s ms ms  s ms ms  s s ms s ms ms ms s s ms ms ms ms  s s s ms ms s s s s s s s s s s ms ms ms s s s s s s h h m m ms s s ms s, 78 s s ms ms s s s ms s m m m m h d m m s s ms s s s s h h d d m m s m  s s d ms s s ms ms ms ms s s s s ms s s s s s s s s s ms s s s ms ms s s s m h s

Berkeley Gas-filled Separator (BGS)

Positive: High efficiency Large suppression of beam and unwanted reaction products

Berkeley Gas-filled Separator (BGS) Negatives: Large focal plane image Poor mass resolution High gamma background at focal plane

ms ms ms s s ms  s ms s s ms ms  s ms ms  s s ms s ms ms ms s s ms ms ms ms  s s s ms ms s s s s s s s s s s ms ms ms s s s s s s h h m m ms s s ms s, 78 s s ms ms s s s ms s m m m m h d m m s s ms s s s s h h d d m m s m  s s d ms s s ms ms ms ms s s s s ms s s s s s s s s s ms s s s ms ms s s s m h s

Scheme What we want to do: Collect recoils at focal plane of BGS Separate by mass Transport low-background region

Space Available 6 ft Cave 2 Beamline BGS Concrete Walls Support Beams

ANL Built Berk. Built Scheme BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box What we want to do: Collect recoils at focal plane of BGS Separate by mass Transport low-background region

> 2 μm metal foil with support grid Window BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

He ~ 100 mbar RF + DC SHE ion retains +1 or +2 charge Cylindrical and conical section Pitch > 0.5 mm, f ~ 1 MHz SHE ions swept out by gas flow Gas Catcher BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

Match acceptance for mass analyzer RFQ Trap BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

Current design based off of segmented rfq Current ion transport simulations agree with velocity distribution and axial distribution approx. Simulations (w/ current exp. param) match current beam properties Is this sufficient? New designs are being explored to minimize timing pulse width RFQ Trap BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

Mass Analyzer: Requirements Fit at least 6 masses on C 3 Ability to determine implantation time High dispersion M/  M of >500 High efficiency Low extraction voltage from RFQ Fit within existing space BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

Mass Analyzer: The Idea Typical mass separators Wien filter TOF ° Magnet Trochoid Separator - FIONA BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

Mass Analyzer: The Idea BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

Mass Analyzer: The Idea BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box Ratio of E wien /E troc

FIONA: Simulations BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box Einzel Lens Electrode: 50 x 20 cm, 500 V/cm Magnet 1.5 T x A= A = V acc = 4000 keV Q = 2+

FIONA: Simulations Det. Box A= BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Einzel Lens Magnet 1.5 T x Electrode: 50 x 20 cm, 500 V/cm A = V acc = 4 kV Q = 2+

What it looks like on the FPD BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box A=

FIONA: Simulations Det. Box A= BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Einzel Lens Magnet 1.5 T x Electrode: 50 x 20 cm, 500 V/cm A = V acc = 4000 kV Q = 2+

How to get time information BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box A=

Facility Layout 6 ft Cave 2 Beamline BGS Concrete Walls Support Beams

Mass Analyzer: Requirements Fit at least 6 masses on C 3 Ability to determine implantation time High dispersion M/  M of >500 High efficiency Low extraction voltage from RFQ Fit within existing space BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

Status and Future Currently building little-FIONA –0.55 T magnet –Xe ion source –MCP detector

FIONA: Simulations BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box Einzel Lens Electrode: 50 x 20 cm, 125 V/cm Magnet 0.5 T x A= A = Vacc = 1 kV Q = 1+

FIONA: Simulations BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box Einzel Lens Electrode: 50 x 20 cm, 125 V/cm Magnet 0.5 T x A= A = Vacc = 1 kV Q = 1+

What it looks like on the FPD BGSWindow Gas Catcher RFQ Trap 1 RFQ Trap 2 Extr. Accel. Mass Anal. Det. Box

Status and Future Currently building little-FIONA –Xe ion source –0.55 T magnet –MCP detector All parts have been ordered/designed Testing and construction will begin in June

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