Georg Hoffstaetter, Professor Cornell University / CLASSE ...

Georg H. Hoffstaetter Future Ligh Sources Workshop – Status of Cornell’s ERL 1 March 2010

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Status of Cornell’s ERL Project

Georg Hoffstaetter, ProfessorCornell University / CLASSE / SRF group & ERL effort

a) Vision for the Futureb) Developments since ERL workshop at Cornell in June 2009c) Planned activities

EducationDesign Research


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Layout and Optics since ERL workshop

1) Quality engineering:(a) shorter building to not cross road, 14 undulators(b) No third, and reduced 2nd floor on x-ray user building(c) Tighter and shorter Turn Around

2) Analysis of one versus 2 turn ERLs3) Decision to build a 1 turn ERL to reduce operational risks1) Keep CESR as is. Later upgrade reduces North emittance by 50%2) Provide a limited number of novel experiments: 14 x-ray beamlines3) Complete layout, magnet lattice, optics: version 8.0


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1) Hard x-rays: 5GeV, competitive current: up to 100mAlow charge per bunch low emittance

2) Working modes: current, emittances, energy spread, bunch lengthA) 100mA, 30/30pm, 2.e-4, 2psB) 25mA, 8/ 8pm, 2.e-4, 2psC) 25mA, 300/10pm, 2.e-3, 1ps in South, 100fs in North beamlines

D) The option of large bunch charge (1nC) with low repetition rate (100kHz),without energy recovery, is not used for x-ray users.up to 1nC is used for accelerator studies, e.g. of XFELO or HGHG FELs

Electron Beam Parameters

300pm

100fs 0

-12%

12%

24%

Energy spread at beam stop


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Lattice choices for Version 8.0

Accelerator R&D area

• Completely reworked model• TA and TB have a smaller bending radius (40m), with mergers.• 0.5mrad soft bends to protect undulators• A diagnostic beamline (DB) is added • All bending magnet lengths adjusted for single power supplies. • Collimators have been added prior to all undulators • Beam abort collimators have been added prior to LB and LA. • BPMs and Corrector Coils have been added everywhere in SA, TA, TB, and NA.• Vacuum pump ports, sliding joints, and gate valves have been added everywhere.


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1) Second InjectorA 30cm kicker has been placedprior to merger bends

2) TA & TB with demerger and mergerComplete

3) Isochronous NA undulator cellsA reverse bend has beenadded to these cells

4) DumpAdded

5) Path length adjuster in TB

Cut

esy

Chr

is M

ayes

Layout and Optics: Major Sections


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6) Vacuum systemPump Ports, Sliding Joints, and Gate Valves have been added (YL & DR)

7) Orbit CorrectionBPMs and Correction coils have been placed everywhere

8) CollimatorsCollimators are placed prior to every undulator, and beam abort collimators have been added

9) Dispersion compensation bends at merger an dumpSecond pass merger dispersion is matched to zero from the last NA cell

10) X-ray absorbers to protect cavitiesCollimators already shield all SR prior to cavities (NA end and TA end)

Layout and Optics: Devices


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11) Spurs in AutoLISPValeri has modified the AutoCADgeneration program to be more general

12) Optimize OpticsMode A (on-crest) is completeMode C (bunch compression) is in progress (CE dispersion and time of flight are difficult to adjust)

13) Adjust magnetic fields for SR lossesNeed to get Bmad to calculate. However, Relative energy change due to SR is ~10-6

14) Efficient Distribution of Power suppliesDR classified and adjusted bend lengths. These have been added to the lattice

Layout and Optics: Miscellaneous


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3.0 m0.57 T, 0.31T

1.0 m0.3 T

1.5 m0.6 T

Layout and Optics: Turnaround murgers


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NA

SA

Layout and Optics: Undulators

Provides 14 high spectral brightness beamlines


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A Huge job – industry connections have to start nowFrom a recent RFP for the electron transport system:

Electron Beamline Elements

Furthermore the SRF linac:

64 cryomodules384 cavities with 7 cells385 RF sources, couplers, etc64 superconducting quadrupoles128 superconducting correctors64 cold bpms…


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1) The engineering firm ARUP is producing a baseline for X-ray buildings, new office space, 14ft diameter tunnel, either ebtbm or mining.

2) UTAP is a consultant on tunneling, will review ARUP in February.

Conventional Construction

ARUP

UTAP


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Conceptual ERL design

accacc

x

inj

x


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Significant IBS and Touschek loss challenges

1) Low emittances create very large beam density and therefore large IBS and Touschek rates leading to emittance and energy spread growth.

2) The relevant beam density is the slice density, not the rms density.

3) Small round emittances allow round, narrow undulator apertures. The IBS Halo then has to be collimated accordingly, inceasing Touschek loss rates.

4) Cornell ERL has large collimators in the tunnel to eliminate loss rates from the arcs, and smaller collimators in front of every undultor.


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14Localization and elimination of nonlinear errors

0.04 0.05 0.06 0.07 0.080.08

0.07

0.06

0.05

0.04

20 18 16 142

4

6

8

10

12

14

16Distortions of a regular grid of beamlets

Before cryomodule

Aftercryomodule


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15 Nonlinear Field Error in the 2-3 regionLocalized by a beam based search

3000 3500 4000 4500 50000.00

0.05

0.10

0.15

0.20

Center of 3rd HOM absorber

Coupler 2

Coupler 3

Coupler 4


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December 17, 2009 Florian Loehl

Removing inner tiles after finding that they charge up at 80K

Stress relief slots

Beamside tiles removed

Consequence of low resistivities of absorber materials:• Completely removed TT2 ferrite because some had fallen off• Tried gold coating of TTE absorbers but coating may fall off

Removed all tiles from the inside of the HOM absorber

Found loose tiles during cryomodule disassembly• Thermal stress tests confirmed

this problem Solved by cutting stress relief

slots in the tiles on top of removing TT2 ferrite


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17Beamline String Assembly

Attach cold couplers to beamline string

Cold coupler

Cavity

Beamline HOM load

He vessel pump port

Attach cold couplers to beamline string

Cold coupler

Cavity

Beamline HOM load

He vessel pump port

Cleanroom assembly fixturing

Gate valve internalto cryomodule

Vacuum vessel interface flangeCleanroom assembly fixturing

Gate valve internalto cryomodule

Vacuum vessel interface flange


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18Technical Details, Justification

and critical needs for R&D Projects

Cornell Electron

Storage Ring Tunnel

a) Continued Gun R&Db) ERL cryomodule constructiona-c) Hi-brightness beam physics

d) ERL Undulatorse) Other X-ray beamline R&D

a)

b)

c)

d)

e)


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Example Main Linac Cost Distribution for E=16.2 MV/m

• High current, multi GeV SRF linacs for ERLs are great for hard x-ray sources• The SRF components are the cost drivers of these novel accelerators• Driving SRF challenges are the dynamics load and theirfor low loss

technology.• HOMs and their control become critical• Microphonis and control becomes critical• It is thus very much worth to invest in these research subjects.

Tunnel RF system Cryomodules Cryogenic plant0

10

20

30

40

50re

lativ

e co

st [

%]

Importance of CW SRF research


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Cornell Electron

Storage Ring Tunnel

a) Continued Gun R&Db) ERL cryomodulec) Hi-brightness beam physics

d) ERL Undulatorse) Other X-ray beamline R&D

a)

b)

c)

d)

e)

Further preconstruction work:Main x-ray ERL cyromodule


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21

PessimisticParameter Units Value

10 MeV Injector (Cornell ICM) Injector RF Power kW 1000Injector Cryo Heat Load W 40

ERL Eacc MV/m 20Operating Temperature K 2Qo 1.00E+10Peak Microphonics Hz 20Qe (Perfect ER) 3.30E+07RF Power per Cavity (Perfect ER) kW 6.4Pdiss per cavity W 41.6Static Load per Cavity W 2Second Pass Phase Deg 179.8Qe (Imperfect ER) 2.10E+07RF Power per Cavity (Imperfect ER) kW 10Total Number of Cavities 337RF Power Overhead % 25ERL RF Power (Perfect ER) kW 2699ERL RF Power (Imperfect ER) kW 4229ERL Cryo Power kW 14.7

Total Total Dynamic Load kW 14.1Total Static Load kW 0.7Cryo Safety Factor % 50Cryo Efficiency ACW/W 800Total Cryo Capacity kW 14.8Total AC RF Power (Perfect ER) MW 7.4Total AC RF Power (Imperfect ER) MW 10.46Total AC Cryo Power MW 17.7Total AC Power (Perfect ER) MW 25.1Total AC Power (Imperfect ER) MW 28.16

OptimisticValue100040

161.8

2.00E+1010

6.50E+072

13.31

179.954.80E+07

2.842110

95012866.0

5.70.450

8006.13.9

4.577.2911.1911.86

ERL SRF Power Consumption


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CLSCESR

DIAMOND

SSRF TLS

Technology transfer to industry

Technology transfer

Turn-Key Systems

Example of Industry Connection:Cornell 500MHz cavities

1999: Cornell University and ACCEL agreed on technology transfer of the 500MHz SRF module2000: 2 SRF modules for NSRRC, Taiwan; delivered operational2000: 2 SRF modules for Cornell, USA; delivered operational2000: 2 SRF modules for CLS, Canada; delivered operational2003: 3 SRF modules for DLS, Great Britain; delivered operational2005: 3 SRF modules for SSRF, China; delivered operational


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30cm long prototype of Delta undulator installed inbeam line #2 at ATF (BNL)

Electron beam image on flag downstream of the undulator

Fundamental harmonics in planar mode Fundamental harmonics in helical mode

Component Prototyping: Delta Undulator


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1) Specify technological choices, cost, and construction timeA) For the electron beamline done following mentioned RFPB) For gun and injector, following Phase 1a and Phase 1b funded prototypingC) For SRF linac following cryomodule construction of Phase 1bD) For x-ray beamlines a set of generic lines will be designed for costing which then can be modified by beamline teams before construction.

2) Cavity operations stability, Quality factor Q0, operations costA) We produce cavities for the Int. CW Cryomodule in DaresburyB) Operation of cavities in our Horizontal Test Cryostat for large Q0 (at NSF)C) Operation of a full ERL cryomodule in Phase 1b.

3) Undulator construction cost and construction time in Phase 1b

Component Prototyping: Phase 1a and 1b


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DUSEL: Cavity design and prototyping for Project-X(ICD1 or ICD2), vendor development and qualification for Project-X and ILC. We are already part of the Project-X team via an MOU.

SRF R&D: T-map analysis as tool for process influences on high gradients and high Q, highest Qs at medium fields, frequent Q degradation in accelerator cryostat environments.

Muon collider: explosion bonded material testing(Nb on Cu for less cost and more heat transfer)with 500MHz cavities for cost and quicker turnaround(for reduced size compared to 200MHz).

SRF R&D synergetic with work for HEP


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26 Knowledge disseminationfor Accelerators

Editor:Frank Zimmermann (CERN)Associate Editors:Georg H. Hoffstaetter (Cornell)Brand M. Johnson (BNL)Senior Assistant Editor:Debbie Brodbar

Focus IssueAccelerator and Beam Physics

Editors:Georg Hoffstaetter (Cornell)Kwang-Je Kim (ANL)Ferdinand Willeke (DESY)


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27Education and workforce development

Undergraduate and graduate students working on ERL injector with physics faculty (Cornell, Wilson lab, L0 area)Graduate Students: 10 accelerator physics, 4 of which SRF

9 high energy physics experiment


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1) Layout – rather order complete2) Operations simulation – much still needed3) BBU – rather complete4) Orbit correction – 1st order analyzed5) Emittance growth – 1st order analyzed6) Shielding – 1nd order analyzed7) Front to end simulation – much still needed8) Sensitivity analysis – 1st order analyzed

Accelerator Analysis and Documentation in aComprehensive Design Report

The full concept is to be documented by this summer in a CDRA) Overview – including short science caseB) x-ray beamline – Generic beamlinesC) Accelerator – Accelerator Physics and Technolgy choicesD) Conventional FacilitiesE) Management – Including SafetyF) Operations – Transition, Reliability

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Georg Hoffstaetter, Professor Cornell University / CLASSE ...

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