required fair/gsi developments in accelerator physics fileexchange Æxy-correlations) ion sources...

O. Kester, KfB Meeting, Darmstadt, 31.08.2011

Required FAIR/GSI developments in accelerator physics

Oliver Kester

Bereichsleiter Beschleuniger

GSI Helmholtzzentrum für Schwerionenforschung


Outline

Introduction The FAIR accelerators and challenges

Developments for the FAIR acceleratorsand the FAIR injectors

Ion sources and linacsHeavy ion synchrotrons and storage ringsStorage rings, special installationsand common systems


FLAIR

Beam intensity increase: Primary beams: x 100 – x 1000(8*1011 uranium ions per spill)Secondary beams: x 10.000

Beams: Anti protonsProtons to uranium, RIBs

Beam quality:Cooled anti proton beamsCooled, intense RIBs

Beam pulse structure:extreme short pulses toquasi continuous

Requirements to conduct world class experiments at FAIR


Some needs!

FLAIR

Superconducting magnets, cryogenics

Rf-systems, timing

Beam dynamics, beam cooling

Diagnostic and collimation

pipeaperture

beam

DA approx. 3.5σ

Dynamic aperture in SIS-100

pipeaperture

beam

DA approx. 3.5σ

pipeaperture

beam

DA approx. 3.5σ

pipeaperture

beam

DA approx. 3.5σ

Dynamic aperture in SIS-100


Ion sources and linacs


List of topics – shopping list I

Ion source development:Extraction and beam transport – correction, collimation,intense rf-proton sources, MeVVA with high rep rate

rf cavity development (low beta cavities):H-type structures, buncher cavities, SC- cavities for cw-linac

Charge state strippersInvestigation of C-stripper foils, alternative scenarios (high pressure gas stripper,plasma stripper systems, liquid metal stripper)

Beam dynamicsSpace charge dominated HI beams in linacs, beam halo formation

O. Kester, KfB Meeting, Darmstadt, 31.08.2011 7

Plasma Gabor lens

Generation of intense ion beamsion source development

Extraction of intense beamsTransport of space charge dominated beams:New LEBT concepts (plasma lens, halo collimation, emittance exchange xy-correlations)

Ion sources and LEBT

ionsPlasma


Charge state stripper for intense heavy ion beams

C-foil stripper- short lifetime at highest intensities, but

highest charge statesgas stripper- High intensity capabilities, but lower charge states- Equilibrium charge state (efficiency)

10 m

mEdge of the foil before irradiation

Unused foil

New concepts:Liquid Li-film or plasma stripper

MIT Plasma window in a test setup at BNL

MIT Plasma window in a test setup at BNL


H-Mode Resonators

IH-Struktur

4-Vane RFQIH-RFQ

CH-Struktur

H11-Mode H21-Mode


IH- and CH-cavity development

FAIR P-LINAC

FAIR-UNILAC-Upgrade cw-LINAC

Boss

ter-L

INAC

(SIS

100)

Hochenergie-LINAC

108 MHz-IH 3:Microwave Studio Analysis

325 MHz-Coupled CH Cavity

216 MHz-SC-cw-LINAC-Demonstrator

325 MHz sc CH-cavityprototype (under fabricationat the ACCELcompany, Bergisch Gladbach, Germany)


Heavy Ion Synchrotrons SIS18 and SIS100and storage rings


List of topics – shopping list II

Beam collimation in high current machinesConcepts (cryogenic systems), materials, use of channeling in crystals, dynamic vacuum degradation – desorption

rf-cavities and rf-systemsMagnetic alloy ring core cavities, barrier bucket systems,bunch to bucket transfer between synchrotrons, bunch merging

Beam dynamics Effects of electron clouds in HI machines, instabilities, impedances (impedancelibrary), beam losses Code development

HV-kicker and pulsed beam optics elements (injection, extractionand beam transfer between ring machines)

Activation and damages of materials by heavy ion irradiation


Beam collimation

Collimation concepts for partiallystripped heavy ions

Collimator materials Vacuum aspects desorptionNew concepts: collimation by crystals

channeling


MA ring core cavities

Examples:• Short bunch from SIS100 (50 ns) • De-bunching in CR High voltage (200 kV) required for

fast bunch rotation

Cooling of ring cores and power coupling

Gap voltage 40 kVLength 1 mRotation time ~ 100 µs


Bunch-to-Bucket Transfer, bunch merging

2 ApproachesWaiting for Proper Phase RelationExact Calculation of Transfer Point andShift Bunches Adiabatically

Damping of instabilities, BPMs, timing system

Example for High Ambitious Beam Manipulations

Merging h=4 → h=2→ h=1, Essential for FAIRHigh accuracy for cavities in phase andamplitude requiredMethods for Damping of all kind of instabilities


Beam dynamics

Periodic crossingof a resonance

z

x

Bare tune

Lattice error or Space Charge Structure Resonance

Slow haloformation

If halo is too large slow beam loss take place

Pipe

z

Questions to be addressedSimulation and measurementson effects of electron clouds on ionbeams in high current machines“Particle tracking” – Simulationover many turns (~1 s) incoherent and coherent effects

Beam loss analysis

Damping of resonances

ImpedancesKicker modules, BPMs, pick-ups,collimators … libraryImpedance test stand?

High performancecomputing


Common systems and special installations


List of topics – shopping list III

Diagnostics systems:Scintillator screens (Beam profile, pepper pot emittance meter),Residual gas beam profile monitorsDC-current transformer using GMR devicesSchottky pick ups

RF systems:Longitudinal rf-feedback systems, high bandwidth Schottky pick ups (tune measurements, stochastic cooling), closed orbit feedback for SIS100,High precision timing

Magnets:fast ramped SC-magnets, cryogenic systems (current leads)HT SC solenoid lensesPulsed magnetic quads(Material sciences)

Generation of secondary particle beamsPulsed power generation for the magnetic horn (p-bar focusing)Target development


Sensitive current transformer for synchrotronsand storage rings using Giant MagnetoResistance (GMR)New high band width Schottky-pickups

bunch-by-bunch information (high f)in SIS100 for very high harmonics

Diagnostic – examples

Theoretical understandingof scintillator materialsChanges of propertiesunder HI irradiationMaterial choicesProperties in different energyrangesSpectroscopic studies


Magnet development

Fast ramped magnets (synchrotrons)Dynamic load and AC heat losses (Synchrotron magnets)Bρ= 100 Tm - Bmax= 1.9 T - dB/dt= 4 T/s (curved)Bρ= 300 Tm - Bmax= 4.5 T - dB/dt= 1 T/s (curved)High field quality, low multipole strengthField calculations, mechanical analysis (coil restraint)Eddy currents and heating of the chamber

HT SC solenoid lenses (in SRF modules for instance)Pulsed beam line elements air coils


RF-systems and timing

Bunch-by-bunch data acquisitionand feedback

Signal processing, digital filterScaling of beam signal

feedback systemSingle bunch oscillation Nonlinear control loop for dampingBroadband cavities (MA ring core) andpower amplifiers Timing

Synchronisation ofsynchrotronsTiming of distributedrf-systems with ns precisionTrigger for kicker systems forbunch to bucket transfer

sec1

5 x 1011 U28+

SIS18

200 MeV/u

1000 MeV/u

18 Tm SIS100

50 Tm

11.4 MeV/u

sec1

5 x 1011 U28+

sec1

5 x 1011 U28+

SIS18

200 MeV/u

1000 MeV/u

18 Tm SIS100

50 Tm

11.4 MeV/u

Bunch-by-bunch data


Summary FAIR accelerator developments

Topics which need to be addressed are:Ion sourcesCavitiesBeam transport and collimationBeam dynamics investigationsRF-controls and feedback systems, timingBeam DiagnosticsNew magnet designsCryogenic systemsTargets and charge state strippersActivation and radiation damage of acceleratorcomponents


Laser acceleration of ions

TNSA of ions at GSILaser target interactionPlasma expansionTransverse focusing with pulsedlenses (strong field)Capture in cavity and bunch rotation

UNILAC beam

Target chamber

Debuncher cavity

Ion beam diagnosticSolenoid

Short pulse diagnostics

Quadrupol

UNILAC beam

Target chamber

Debuncher cavity

Ion beam diagnosticSolenoid

Short pulse diagnostics

Quadrupol


Additional slides


The modularized start version (Modules 0-3)

Modul 0SIS100

Modul 1CBM,APPA

Modul 3Antiproton-target, CR,p-Linac, HESR

Modul 2Super-FRS

required fair/gsi developments in accelerator physics fileexchange Æxy-correlations) ion sources...

Documents