Status BESSY VSR

Pierre Schnizer

on behalf of the BESSY VSR Team

SFR, 25. June 2018, Novosibirsk

BESSY VSR: PROVIDING A VARIABLE PULSE PATTERN

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Target: provide to BESSY VSR users:

• Large average current: 300 mA

• Short and long pulses at the same time

𝑝ℎ𝑜𝑡𝑜𝑛𝑠

𝑠 𝑚𝑚2 𝑚𝑟𝑎𝑑2 0.1 %𝐵𝑊

Peak brilliance Std long pulses 1.2 ∙ 1022

Std short pulses 1.7 ∙ 1022

Long camshaft 4.0 ∙ 1022

Short camshaft 5.1 ∙ 1022

Requires quite a few activities

• SRF Cavities ← the core

• Beam diagnostics → feedback

• Booster → hit the short buckets

• Auxiliaries:

details

follow

3Pierre Schnizer et al. SRF in a dirty accelerator

BESSY VSR –THE IDEA…

0.5 GHz NC x 4

1.5 GHz SC x 2

1.75 GHz SC x 2

bunchlength ~α

𝑈′

low-α

(magnets)

(cavities)

4Pierre Schnizer et al. SRF in a dirty accelerator

CSR DRIVEN INSTABILITY THRESHOLD

𝜎 = const. 𝐼th ~ 𝛼

σ0~α

𝑈

zero-current bunch length

threshold current scaling:

uncharted territory included !

5Pierre Schnizer et al. SRF in a dirty accelerator

A FILL PATTERN SERVING MANY DIFFERENT USERS

• charge variation ~ x 50

• charge density variation ~ x 10

• uncharted territory included

VSR PROJECT STATUS: SUPERCONDUCTING CAVITY SYSTEM

• R&D started 2016 / Experience share with bERLinPro

• Models built and tested

• Copper model

• Sc single cell model

• HOM Loads

• Result:

• Reached 15 MV / m already at first test

• Limit: Field emission, Test Station

• Cavity design: sound and verified

• Tendering:

• SC cavities soon / couplers following swiftly

• Cryostat design running6Courtesy of A. Veléz and his team

7Pierre Schnizer et al. SRF in a dirty accelerator

Sc. Cavities in the ring

Dipole end Synchrotron light

Shading off bellows

• Synchrotron light density: ~ W/mm³

• Available space: rather limited → specialised bellows

• Operating cavities: 20 MV/m, 300 mA beam current

• Injecting into short bunch buckets

• Controlled beam loss

• Timing & Synchronisation

• Analysing the beam pulse length

VSR PROJECT STATUS: BESSY II UPGRADE

• Challenges: Booster

• Matching short buckets (1 ps ~ 0.3 mm)

• bunch shortening with

additional cavities (Petra 5 cell, to be ordered)

• Further activities

• Diagnostics upgrade

• Beam separation

• Selection: short or long bunches

• Chopper wheel

upgrade of existing design

collaboration to be established

• TRIB’s: Successful user operation

8Courtesy of M. Ries, P. Goslawski et al

VSR PROJECT STATUS: MACHINE UPGRADE

• Reliable SRF Cavity operation → Vacuum system upgrade

Minimizing Particulates

Residual vacuum pressure @ module

• Timing & Synchronisation

combined with bERLinPro

• Machine protection

• In particular for

SRF System

• energy transfer

• Radiation light9Courtesy of A. Schälicke et al

VSR PROJECT STATUS: AUXILIARIES

• Cryoplant:

• Procurement running

• 186 W @ 1.8 K

• Compressor hall

• Planning running

• To be finished Q1/20

• 1.5 GHz and 1.75 GHz 15 kW Amplifiers

• Procurement running

• Testinghall for module test station / clean room

• Planning running10

Batavia plant (similar)

Courtesy of W. Anders et al

VSR STATUS: PLANNING

• Plans for work packages ~ 1500 items

• Interdependencies traced with Links

• Cost book established

• Risk mitigation actions:

• Thorough testing of SRF cavities

• Hot spare module

• Reliability analysis ongoing: e.g. redundancy

requirements for cryoplant

• 3 Funding pots: automatic cost aggregation for

• Funding sources

• Accumulated cost per work package

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HERZLICH WILLKOMMEN

am Helmholtz-Zentrum Berlin

VSR PROJECT: ROADMAP

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July 2017 - project decision

Jan 2018 - project start

→ Q3 / 2021 - preparation of pre-phase module

~ 4 – 5 month - dark time due to

module installation

SRF commissioning

System tests

Beam commissioning (partly with “friendly user operation”)

→ Q3 / 2022 - preparation of full module

~ 4 – 5 month - dark time

VSR PROJECT

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Institute for Accelerator Physics and Department of Accelerator Operation, HZB

Institute for SRF Science and Technology (J. Knobloch), HZB

and at JLAB, Cornell, BNL, BINP, DESY, HZDR, TU Dortmund, U Rostock, U Mainz, U Bonn, and …

Michael Abo-Bakr Wolfgang Anders Terry Atkinson Yvonne Bergmann Thomas Birke Markus Bürger Marc Dirsat

Olaf Dreßler Volker Dürr Pablo Echevarria Hartmut Ehmler Fjodor Falkenstern Jörg Feikes Nadine Fischer

Roland Fleischhauer Thomas Flisgen Alexander Föhlisch Andre Frahm Holger Glass Hans-Walter Glock

Felix Glöckner Frank Göbel Kai Godehusen Rainer Görgen Paul Goslawski Mario Haucke Jochen Heinrich

Svenja Heling Andreas Heugel Harry Hoffmann Karsten Holldack Ji-Gwang Hwang Andreas Jankowiak

Christian Jung Christian Kalus Kerstin Kalus Thorsten Kamps Sascha Klauke Guido Klemz Doreen Kniebel

Jens Knobloch Marten Koopmans Felix Kramer Katharina Krämer Oliver Kugeler Bettina Kuske Peter Kuske

Karim Laihem Nicole Leuschner Ji Li Klaus Ludwig Dimitriy Malyutin Aleksandr Matveenko Tom Mertens

Gert Meyer Gregor Mielczareck Dirk Mielke Ingo Müller Roland Müller Axel Neumann Klaus Ott

Lutz Pichl Henry Plötz Joachim Rahn Markus Ries Stefan Rotterdam Roswitha Schabardin

Andreas Schälicke Steffen Schendler Gregor Schiwietz Tobias Schneegans Bernhard Schriefer

Dirk Schüler Oliver Schüler Michael Schuster Ines Seiler Emmy Sharples Hannes Stein Yegor Tamashevich

Andranik Tsakanian Jan Ullrich Andriy Ushakov Adolfo Velez Ines von Scheibner Florian Wichert Stefan Wiese

Daniel Wolk Godehard Wüstefeld Sabine Zienecke

15

1-cell prototype testing

(SVTA)Full cavity testing (LVTA)

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Validation of the models : Fabrication & testing of prototypes

• Test fabricability of cavity with

end-groups

• Measure Q curve vs E curve

• Validate simmulation techniques

BESSY VSR CAVITIES

1.5 GHz BESSY VSR Single cell prototype

• Confirm multipacting free design

Y. TamachevicPoster

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Call for tender

Contract signed

First 1.5 GHz cavity tested

Module available for installation

1.75 GHz cavities available

Series Module available for installation

Impedance test installation, validated

Petra cavities installed

Cryoplant tender, commissioned

Amplifiers: contract signed,

commissioned

Layout of the facility: Bunker

VSR-BAU-F00421.0

Layout of Facility Ground Floor

Layout of Facility 1.st Floor

2. BA Testinghalle – Grundriss KG

Vertical layers

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3D Skizze: Führung der Medienversorgung

Bunker „vorletzte Version“

Labyrinth nicht lange genug

• Hier Ziel: Überprüfung der

Rohrführung

Flexible

Nexans Leitung

250 mm Rohr Modell für

• Kryorohr 16 mbar

• Rechteckhohlleiter

• Laserrohr

Lichte Höhe im Bunker

momentan 2.1 m

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THE VARIABLE PULSE PATTERN

• Antagonistic requirements

• short pulses

• High average flux

• Long and short bunches

• Beating frequency

scheme

• Implemented:

1.5 and 1.75 GHz sc. Cavities

• Installed in a

cryomodule in one

low beta straight26