Progress of HCC Design and Simulation - PowerPoint Presentation

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Progress of HCC Design and Simulation - PPT Presentation

K Yonehara APC Fermilab MAP 2014 Spring Meeting Fermilab May 2731 2014 1 Contents Current working item since MAP DOE meeting Highlights in current activities Deliverable plan HCC Design and Simulation ID: 796632

design hcc simulation map hcc design map simulation 2014 spring meeting cooling beam gas yonehara test channel plasma window

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Slide1

Progress of HCC Design and Simulation

K. YoneharaAPC, Fermilab

MAP 2014 Spring Meeting,

Fermilab, May 27-31, 2014

Slide2

Contents

Current working item since MAP DOE meetingHighlights in current activitiesDeliverable plan

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide3

List of Current W

orking Item since MAP DOE ‘14

ItemDescription

Design Cooling Elements

• Update initial cooling channel (see Yuri’s talk)• Update initial matching section (see Cary’s poster)

• Resume helical bunch merge system (see Amy’s talk)

Machine

Development

• Prepare dielectric

loaded gas-filled RF cavity test (see Ben’s talk)

• Investigate gas-plasma chemistry (plan to submit to PRSTAB) (see Ben’s poster)

• Develop HCC magnet design (see Mauricio’s talk)

• Develop double layered Nb3Sn winding technology (see Mauricio’s talk)

• Study various HS coil configurations (see Steve’s talk)

• Design RF window (see Alvin’s talk)

• Study beam loading effect (see Alvin’s talk)HCC Theory• Muon beam dynamics interacting with gas-plasma (see Moses’ poster)• Theoretical investigation of helical cooling channel in terms of the generic cooling theory• Translate HCC theory to the generic cooling theory• Optimize emittance evolution

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide4

Three Highest Priority Items

in Cooling Simulation Effort

Initial FOFO Snake Cooling Evaluated the channel with the same initial muon beam distribution as Valeri’s rectilinear channelPublished the result (MAP-doc-4377)See Yuri’s talk for detailMatch-In ChannelImprove transmission efficiency 60 → 80 %

Tune more parameter spaces to make better transmissionSee Cary’s poster for detailHelical Bunch Merge Channel Update the optics to fit to the present MAP IBS beam parameter

See Amy’s talk for detailHighlights in c

urrently working items (I)

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide5

Another Highest Priority I

temsin Experimental & Design Efforts

HCC magnet design and status of double layered Nb3Sn See Mauricio’s talkStudy various HS configurations See Steve Kahn’s talkDielectric Loaded HPRF cavity testThe test cavity is ready for low power sample measurementWe also plan to have a beam test

See Ben’s talkRF window study Estimate required thickness to mitigate thermal expansion and Lorentz Force Detuning (LFD) effectsSee Alvin’s talkBeam loading effect Estimate HOM + fundamental mode wake fields in the cavity

See Alvin’s talkGas-Plasma simulation Influence gas-plasma motion on beam dynamicsSee Moses’ poster

Highlights in currently working items (II)

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide6

Study HCC from theoretical aspects

Translate HCC theory into generic cooling theorySystematic way to study HCC

Evaluate non-linear dynamics, e.g. Space charge effect & Plasma lens, etcEstimate cooling performance including with RF window, beam diagnostic material, spacing, etcCompare HCC with VCC from analytical point viewImport/Export key concept

Optimize HCCModulate optics to reach goal emittanceMaximize transmission efficiency Optics parameters should be bound by practical engineering parameters

Highlights in currently working items (III)

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide7

Translate HCC theory

into generic cooling theory

Emittance evolution

Equilibrium

emittance

Cooling decrements

and

are the function of dispersion

= 0.5 m,

= 650 MHz, Gas Pressure = 160

atm

@ 300 K

E = 20 MV/m, RF window thickness = 60

m, 10 RF cells /

Solid line is the prediction (NOT fitting!)

o to Appendix to see detail analytic formulae

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide8

Equilibrium emittance

vs RF window

Modify radiation length and

/dx to

involve RF window dependence

Blue: Generic cooling theory

Equilibrium

emittances

in a 650 MHz HCC

Magenta: HCC theory

Red: Cooling simulation

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide9

Equilibrium

mittance in B space

(HCC period) = 0.65 m

0.6

0.55

0.5

0.475

0.45

0.425

0.4

(HCC period) = 0.65 m

0.6

0.55

0.5

0.475

0.45

0.425

0.4

Present design limit

Injection angle = 45 degrees (

= 1)

RF window thickness = 60

Present design limit

0.6

0.55

0.5

0.475

0.45

0.425

0.4

0.65

0.4

0.425

0.45

0.475

0.5

0.55

0.6

Hardest requirement in HCC magnet design is making huge field gradient to reach low trans. emit.

However, low long. emit. can be made in low field grad. →

It is a clue of a new cooling scenario

Achievable field grad. strongly

depends on the size of RF cavity

Slide10

Equilibrium

mittance with various kappask (=

pj/pz) = 0.9

0.95

1.05

1.1

1.0

(HCC period) = 0.4 m

RF window thickness = 60

pj/

pz) = 0.9

0.95

1.01.05

1.1

0.95

.05

1.1

1.0

0.95

.05

1.1

1.0

0.9

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide11

Possible cooling scenario

End of Front-end

Gas-filled FOFO Snake

HCC 325 MHz

HCC 650 MHz

HCC 975 MHz

Design goal

Present achievement

Match-out

Match-in

After bunch merge

(displaced for clarity)

Emittance Exchange

(e.g. in Match-out channel)

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

New evolution

= 0.36 m,

= 11 T

Slide12

Plan by September 2014

Technology Development

RFDL HPRF cavity testRF window studyMagnetDesign HS coil based on double layered Nb3Sn test resultDesign/Consider beam diagnostic systemDesign and SimulationInitial cooling channel, match-in, and helical bunch merge channel

Smooth l HCC to maximize transmission efficiencyCurrent goal length 200 mCritical item in cooling physicsStudy wake field effect

Beam dynamics with plasma motion

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide13

Appendix

Slide14

Present Gas-Filled

RF 6D Helical Cooling Channel Design Working G

roup14

Original: 9/14/13Modified: 2/07/13

K. Yonehara1S. Kahn2

Y. Derbenev3R. Johnson2

V. Morozov

C. Ankenbrandt

D. Neuffer

Y. Alexahin

G. Flanagan

2J. Tompkins1S. Kahn2A. Tollestrup1M. Chung1A. Moretti1

B. Freemire1,4Y. Torun4K. Yonehara1

R. Samulyak5,6K. Yu6

1Fermilab2Muons, Inc.

Jlab

IIT

BNL

STONY BROOK

Supported by MAP & SBIR/STTR

& Lee

Teng

Internship program

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide15

skew parametric ionization cooling channel

MAP Spring Meeting 2014,

Slide16

PIC Concept

Half-integer resonances with simultaneous focusing in both planes

Absorber limits angular spread at the focal points

An order of magnitude smaller transverse emittance than in conventional case

Correlated optics

Absorbers

Parallel beam envelope restored

Beam envelope

without absorbers

(RF cavities not shown)

Muons

, Inc.

Slide17





tracks in twin helix



PIC Developments

Twin-helix channel with correlated optics

Superposition of pairs of helical harmonics and straight multipoles

Simulations ignoring stochastic effects prior to aberration compensation

Aberration compensation

Non-linear resonance issue: many correcting harmonics make motion unstable

e.g. lead to many non-linear resonances in case of correlated optics making compensation very challenging

Absorbers

RF cavities

Muons

, Inc.

Slide18

Extension to

Skew PIC

: the principles

Plane snake orbit

Pursuing to build

correlated optics

but

for

radial motion

only

This feature is realized by adding

skew quads

for strong

x-y coupling

Azimuthal motion is not correlated (a free tune subject of a design choice; tune spread is irrelevant to the radial PR)

2d snake-dispersion is focused periodicallyPose weak Parametric Resonance quads to provide and control beam gradual focusing at zero dispersion pointsBeam envelope still be not axially-symmetric, thus leaving one with possibility use of multipoles to compensate for radial aberrations

Muons

, Inc.

Slide19

Extension to

Skew PIC

: advantages

2d-dispersion is not in resonance with transverse oscillations (big release for conceptual design!)

Ease creation of a dispersion required for chromatic compensation

(a big advance

Effective reduction of the two-dimensional task of compensation for aberration to the one-dimensional (radial) one (other big release and advance!)

A drastic cutback in the required group of compensating

multipoles

(big

simplification

in design/construction/control)!

Other advantages: intrinsic equating of 1) PR rates in two planes; 2) transverse cooling decrements Using thin tilted absorber plates installed at zero dispersion points) instead of “micro-wedges” (-way to control emittance exchange – promoted by R. Palmer): a critically important technical reduction! – yet a conceptual simplificationSkew PIC is easily transformable to the succeeding REMEX (at use of

method !)Linear SPIC concept has been

proven-in-principle in basics (compatibility of the pointed principal properties with simplecticity

)

Muons

, Inc.

Slide20

What is next

Accomplish studying the linear SPIC dynamics and design

Develop the non-linear

amilton’s analysis

Utilize

compensation for

aberrations theory:

impose the required

multipoles

Utilize cleaning

for dangerous non-linear resonances if needed

Implement

parametric resonance

Find a feasible technical

concept of magnetic lattice for SPICDemonstrate (in tracking) expected dynamical features in SPIC channelImplement an adequate RF stuffStudy IC with G4BLDevelop the related beam & optics controlAt success, extend SPIC to REMEX

Muons

, Inc.

Slide21

machine development

Slide22

Cost Effective

RF Power Source: Magnetron

Muons

, Inc. promoted a 650 MHz magnetron for PIP-2 (a.k.a. Project-X)

Developed and demonstrated a new method of control of magnetrons allowing extremely good stability

Expected phase stability less than 1 degrees

Can make a new MW scale precisely stable RF source

Kazakevich

et al., NA-PAC’13, 966

Kazakevich

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide23

HPRF Beam T

est at MTA23

400 MeV

H- Beam

Gas-Filled RF cell

Multi-Tesla

solenoid

Proton beam test at MTA

• Test H2, D2, N2, He

• SF6, Dry Air as electronegative gases

• B = 0 or 3 Tesla

• Vary peak RF E, 5 – 50 MV/m

• Vary gas pressure, 20 – 100

atm

• Vary beam intensity (Full intensity 54 mA)

RF pickup 1RF pickup 2

RF power coupler

Optical feedthru

Gas inletHCC Design and Simulation,MAP Spring Meeting 2014, K.

Yonehara

Slide24

Beam

-Induced Gas Plasma Experiment

February 20, 201424

RF amplitude with beam-induced gas plasma

• Ionization electrons consume RF power • A small amount of electronegative dopant (O

2) can greatly reduce the plasma loading

• No RF degradation due to magnetic field

▷ e-H2 Collision frequency ≫

Larmor

frequency

DA: Dry Air (20 % O

)

Measured plasma loading

• Measured plasma loading effect is 0 ~ 70 % lower than expected in pure H2 gas ▷ Density effect• Plasma loading is 50 times lower by adding 1 % O2HCC Design and Simulation,MAP Spring Meeting 2014, K. Yonehara

M. Chung et al., PRL 111, 184802 (2013)

Slide25

Dielectric Loaded

Gas-Filled RF Test

Dielectric strength of Al

3 (99.8%)

Measured maximum available RF gradient in

an Al

(Alumina) loaded gas-filled RF test cell

as a function of N2 gas pressure

Maximum surface

RF field

14 MV/min this testBreakdownlimit of N2 gas at low pressureAlumina sampleHPRF test cellL. Nash et al.,IPAC’13

• Compact RF cavity is required for a short-length 6D cooling channel

• Dielectric loaded gas-filled RF cavity is proposed

· Increase RF capacitance by adding dielectric material to shrink the cavity size → Verified · Gas can suppress the surface breakdown of dielectric material

→ Verified

Simulated E

distribution in

DLRF TC

(half cylinder)

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide26

Future HRRF experiment

Dielectric loaded gas-filled RF test

Dielectric material sample test

Beam test

Cold RF test

RF window test

MTA proton beam

Dielectric loaded RF test cell

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara

Slide27

Thermal calculation of RF Window

in Gas-Filled RF Cell

h = 10 W/(m2 K)

dT = 180 °C

160 atm GH2

atm

Air

= 10 °C

Marhauser

E = 24 MV/m

• Thermal gradient is worse in a vacuum RF than 1 atm Air• While dense gas acts as a coolant thus, significantly reduces temp. rise on the windowHCC Design and Simulation,MAP Spring Meeting 2014, K. Yonehara

Slide28

generic cooling formulae

MAP Spring Meeting 2014,

Slide29

Key formulae in generic cooling

and HCC theories

Transverse beta tune in HCCAverage transverse beta functionLongitudinal beta function in HCC

Equilibrium emittances

where

HCC Design and Simulation,

MAP Spring Meeting 2014, K.

Yonehara