1. Roger Ruber, Volker Ziemann, Gergana Hamberg Uppsala University
FREIA Facility for Research Instrumentation and Accelerator Development
Roger Ruber, Volker Ziemann, Gergana Hamberg
Uppsala University

2. The European Spallation Source
29-Sep-2011
Roger Ruber - FREIA Test Facility

3. The European Spallation Source (ESS)
Lund, Sweden, next to MAX-IV
5 MW pulsed neutron source
14 Hz rep. rate, 4% duty factor
>95% reliability for user time
Cost estimates (2008 prices)
1,5 G€ / 10 years
Time frame:
2 years design update (TDR) (overlap with 5y prepare-to-build)
5 years construction
first neutrons 2019
High intensity allows studies of
complex materials, weak signals, time dependent phenomena
29-Sep-2011
Roger Ruber - FREIA Test Facility

4. ESS Cost Estimates Investment: 1478 M€ / ~10y Operations: 89 M€ / y
Decomm. : 346 M€
(Prices per )
29-Sep-2011
Roger Ruber - FREIA Test Facility

5. International Collaboration
Sweden, Denmark and Norway
covers 50% of cost
17 Partners today
The remaining ESS members states together with EIB cover the rest!
29-Sep-2011
Roger Ruber - FREIA Test Facility

6. ESS Layout and Energy Usage
Artists Impression
ESS Layout and Energy Usage
Klystrons
~30 MW
Liquifiers
69 GWh/y
Ion source
7 GWh/y
Instruments
5 GWh/y
Accelerator
123 GWh/y
Target station
11 GWh/y
29-Sep-2011
Roger Ruber - FREIA Test Facility

7. Sustainable Energy Management
Responsible
Renewable
Goal: carbon neutral
Recyclable
29-Sep-2011
Roger Ruber - FREIA Test Facility

8. The Master Schedule
29-Sep-2011
Roger Ruber - FREIA Test Facility

9. The Accelerator single pass linear proton accelerator
5 MW p+: 50 mA, 2.5 GeV, 14 Hz, 2.86 ms
< 1 W/m losses
95% user beam time reliability
normal conducting (room temperature)
electron cyclotron resonance (ECR) source
radio-frequency quadrupole (RFQ)
drift tube linac
superconducting (liquid helium temperature)
double spoke resonators (DSR)
elliptical cavities
© CERN CDS
29-Sep-2011
Roger Ruber - FREIA Test Facility 9

10. RF Generation and Distribution System
200 cavities ( MHz)
200 RF systems: modulator, klystron, distribution, controls
5 MW beam → 20 MW RF, (losses and LLRF overhead)
R&D objectives
energy efficiency and operational costs reductions
produce technical design, with cost estimate, to start tendering
29-Sep-2011
Roger Ruber - FREIA Test Facility 10

11. Test Stand Objectives
Prototype baseline design and acceptance testing of production elements
ion source
RFQ, bunchers, DTLs, spokes and elliptical cavities
power couplers, tuners, cryo-modules
RF system including power sources, distribution and controls (LLRF)
200 Accelerating structures and RF distribution points
minor fault might create a major risk
must ensure low beam loss operation
to prevent activation of accelerator components
major part of the accelerator budget
must be cost, energy and resource effective for construction & operation
Training of future staff
prototyping moved to 5 years P2B (in parallel to 2 years ADU)
29-Sep-2011
Roger Ruber - FREIA Test Facility

12. Examples of Issues to be Addressed
High losses in the linac
Action: Comprehensive studies of beam dynamics (simulations and theory)
Poor reproducibility in cavity performance
Action: Quality control during manufacturing and prototyping of a sufficient large number of cavities
Limits in cavity performance due to field emission
Action: Comprehensive design studies, prototyping and comprehensive tests of cavities and complete cryomodules
Limits in RF system performance
Action: Prototyping, sufficient contingency in design
Delivery and installation RF system
Action: Study alternatives, staging of beam power and energy
29-Sep-2011
Roger Ruber - FREIA Test Facility

13. FREIA Test Facility at Uppsala University 4 Years development phase
prototyping of LLRF and HLRF solutions
training of students and staff
4 Years development phase
2011 – 2012: design, tendering
2013 – 2014: commissioning, R&D RF systems (components & concepts)
2015 and beyond: energy efficiency, component testing
Hardware:
HV pulse modulator
704 MHz klystron (1.5 MW)
RF distribution system
LLRF system
2 SRF elliptical cavities
helium liquefier
29-Sep-2011
Roger Ruber - FREIA Test Facility

14. New Experiment Hall
29-Sep-2011
Roger Ruber - FREIA Test Facility

15. FREIA RF System HV pulse modulator Klystron HLRF distribution LLRF
14 Hz, 3.5 ms
Klystron
704 MHz, 1.5 MW peak
2.86 ms pulse
HLRF distribution
0, 1, 2 cavities
fast vector modulator
LLRF
RF regulation,
cavity tuning
29-Sep-2011
Roger Ruber - FREIA Test Facility

16. FREIA Cryogenic System
Multiple users
transport dewar filling
horizontal test cryostat
future vertical test cryostat
Liquid helium
~140 l/h peak load at 4 K
~2000 l storage dewar
~8 g/s, 80 W peak load at 2 K
Recovery system
30 m3/h average
50 m3/h peak load (minutes)
29-Sep-2011
Roger Ruber - FREIA Test Facility

17. FREIA Test Cryostat
internal volume for 2x 704 MHz cavities (3.5 m x Φ 1.1 m)
to test two-cavities-per-klystron concept
operation temperature range 1.5 – 2.2 and 4.2 – 4.6 K
base on existing designs: CHECHIA, CryoHoLab, HoBiCat or prototype ESS cryostat design?
29-Sep-2011
Roger Ruber - FREIA Test Facility

18. HoBiCaT (HZ Berlin, BESSY)
J. Knobloch et al., HoBiCaT – A test facility for superconducting RF systems, Proc. SRF’03.
internal volume 3.5 m x Φ 1.1 m
range 1.5 – 2.2 K, 4.2 K
stability ±0.1 mbar (1.8K), 1mbar (4.2K)
integrated 2K cold box
supply: 180 l/h at 4.2 K (Linde TCF50)
pumps for 80W at 1.8K
LN2 thermal shield cooling
50 l
2K cold box
29-Sep-2011
Roger Ruber - FREIA Test Facility

19. CryHoLab (Orsay, CEA Saclay)
H. Saugnac et al., “CryHoLab”, a new horizontal test cryostat for SCRF cavities, Proc. SRF’99, Santa Fe, New Mexico, USA
29-Sep-2011
Roger Ruber - FREIA Test Facility

20. CHECHIA Cryostat (CEA Saclay, DESY)
P. Clay et al., Cryogenic and electrical test cryostat for instrumented superconductive RF cavities (CHECHIA) Proc. CEC/ICMC’95, Columbus, Ohio, USA (TESTLA-95-21)
one horizontal positioned TTF cavity
29-Sep-2011
Roger Ruber - FREIA Test Facility