1. Cryogenics at the European Spallation Source ESS
Wolfgang Hees
ESS - Group Leader Cryogenics & Vacuum
, TTC meeting, Beijing

2. ESS in general
Neutrons
Organisation & Schedule
Linac
Cryogenics
Cryomodules
Segmentation

3. European Spallation Source – a pan-European research centre
- a world-leading facility for materials research and life science
- scientists will use neutrons to study the materials of tomorrow – from plastics and proteins to motors and molecules
- spallation uses a high-power proton beam to extract neutrons from a heavy metal target
➼ average beam power 5 MW
➼ proton energy 2.5 GeV
➼ 2.86 ms pulses @ 14 Hz
➼ length: 500 m
➼ 1 target station
➼ 22 instruments

4. ESS in Lund
Neutron Source and Synchrotron Light Source on same site: ESS & MAX-IV
World leading cluster of science facilities: XFEL, PETRA at 300 km
Excellent communications: minutes to CPH airport destinations - high speed rail link to Stockholm & Hamburg - a crossroads for 10 european countries
Öresund region: an intellectual capital - 10’000 scientists ’000 students - Lund university is 3rd largest attractor of EU R&D funds 4

5. High time average and peak flux
Berkeley 37-inch cyclotron
350 mCi
Ra-Be source
Chadwick
1930
1970
1980
1990
2000
2010
2020
105
1010
1015
1020 1
ISIS
Pulsed Sources
ZINP-P
ZINP-P/
KENS
WNR
IPNS
ILL
X-10
CP-2
Steady State Sources
HFBR
HFIR
NRU
MTR
NRX
CP-1
1940
1950
1960
Effective thermal neutron flux n/cm2-s
(Updated from Neutron Scattering, K. Skold and D. L. Price, eds., Academic Press, 1986)
Evolution of the performance of neutron sources
FRM-II
SINQ
SNS
ESS
J-PARC

6. ESS Organisation CEO C. Carlile Machine Director Science
Data Management
ESS AB Board
CEO
C. Carlile
Accelerator
Target
Conventional Facilities
Instruments
Administration
Director
Machine Director
Science
Steering Comm (STC)
Adm Financial Comm
Programme Director
Programmme Office
Science Adv. Comm
Technology Adv. Comm
Preconstruction
Construction
Operation Phase
Collaboration Partners
Neutron Science

7. International collaboration
Sweden, Denmark and Norway
cover 50% of cost
17 Partners today
The remaining ESS members states together with EIB cover the rest!

8. in global research networks
Technical R&D
in global research networks
SRF:
CEA Saclay
IPN Orsay
Rostock University
Royal Holloway
CERN
DESY / XFEL

9. A sustainable research facility
Responsible
Carbondioxide:
ton/year ⇓
Energy efficiency
Responsible
Carbondioxide:
ton/year
Renewable
Carbondioxide: ton/year
Högsta temp: 118 GWH
All värme: 215 GWh = villor
Recyclable
Carbondioxide:
ton/year

10. ESS construction cost estimates
Investment: M€ / ~10y
Operations: 106 M€ / y
Decomm. : 346 M€
(Prices per 2008)
250 M€
2011
2020

11. ESS personnel
450
2011
2025

12. Accelerator Milestones & Cryomodules
2012
2013
2014
2015
2016
2017
2018
2019
concept
design
prototype
series
design
← first protons on target
manuf.
inst.

13. ESS linac tunnel

14. LINAC layout Length (m) Input Energy (MeV) Frequency (MHz) Geometric β
# of Sections
Temp (K)
RFQ 5
75 × 10-3
352.2 -- 1
≈ 300
DTL 19 3
Spoke 58 50
0.50
18 (2c)
≈ 2
Low Beta
108
200
704.4
0.70
16 (4c)
High Beta
196
500
0.90
14 (8c)
HEBT
100
2500 25

15. The Cryogenic Systems of ESS
➚ almost an LHC cryoplant
linac: extrapolation estimate: 14 equiv. supplied at 2 K + screen temps.
target: TD heat load calculations: 68 (15 equiv.) supplied at < 20K
instruments: interpolated from ILL: 17 l/h LHe (35 l/h peak) → liquefier cap. 45 l/h 200 l/h LN2 (delivery based solution)
labs, test stands etc ...
➚ and another one

16. Cryomodules Physical boundaries, tunnel geometry etc ...
ESS linac tunnel:
cross section: 5 x 3.5 m2 TBC
length: 522 m (390 m cold linac)
slope: none
space for external cryoline, valveboxes, jumper connections
space for CM with diameter ∼ 1200 mm
space for CM transport
DRAFT

17. Specification temperature: 2 K 8 cavities, 2 sc quads
alignment: 0.5 mm
reduced heat load
transportable (<12.3 m)
possibility to service indiv.
input from beam physics dept. 17

18. Reducing heat load Hybrid design (proposal) open questions:
assess advantages - heat load gains vs cooling load & cost
cryogenic design - cooling of utility module
mechanical design - vacuum jacket, bellows etc ...

19. Segmented Design & Warm Quads
Choice between hybrid design and segmented design is based on a number of criteria to be evaluated, e.g. heat load, costs, etc ...
Decision about segmented design will be followed by the decision about cold or warm quadrupoles.

20. ESS Cryomodule Design Design of spoke CMs
IPNO (Duthil et al) preliminary work has started
Design elliptical CMs
limited options: JLab, FNAL, IPNO
negotiations ongoing
Manufacturing and testing
prototype at CERN ?
series re-use of XFEL line Saclay/DESY ?
options being studied

21. Decide on cryomodule concept ! (January 2012)
Next steps
Decide on cryomodule concept ! (January 2012)
Contract a designer for the elliptical cryomodules ! (March 2012)
List requirements, write spec ! (May 2012) 21

22. We’re hiring cryogenic engineers !
We’re hiring cryogenic engineers !