2. n Physics at ESS and the upgrades needed for the ESSnuSB
Elena Wildner, CERN
For the ESSnuSB Collaboration

3. European Spallation Source, ESS
Artist’s view of the
European Spallation Source, ESS
Lund, Sweden
9/9/2016
E. Wildner, CERN, NOW 2016

4. ESS Linac Linac ready by 2023: full power and energy (5 MW, 2 GeV)
Upgrade (n+n)
Upgrade energy
10 MW
2 GeV
2.5 GeV
62.5 mA
50 mA
< 2.86/4 ms
≥ 28 Hz
45 MV/m
352.5 m
ca 70 m ms
P +
P+ and H-
P+ and H-
Linac ready by 2023: full power and energy (5 MW, 2 GeV)
p.o.t. per year
9/9/2016
E. Wildner, CERN, NOW 2016

5. ESSnuSB layout on the ESS site
2.5 GeV
9/9/2016
E. Wildner, CERN, NOW 2016

6. ESS construction site February 2016ν p n H-
9/9/2016
E. Wildner, CERN, NOW 2016

7. The MEMPHYS detector MEgaton Mass PHYSics
(~20xSuperK)
(30 % optical coverage)
Neutrino Oscillations (Super Beam)
Proton decay
Astroparticles
Understand the gravitational collapsing: galactic SN ν
Supernovae "relics"
Solar Neutrinos
Atmospheric Neutrinos
JHEP 0704 (2007) 003, [hep-ph/060317],
arxiv.org/pdf/ pdf & EUROnu collaboration (EU)
Near Detector at 500 m: WC technology, 5m radius, 10m long
A. Burgman, A neutrino detector design-a simulation study on the design of the cherenkov near detector of the proposed ESSnuSB [M.S. thesis], Lund University, Lund, Sweden, 2015.
E. Wildner, CERN, NOW 2016
9/9/2016

8. Mines in Scandinavia
The Garpenberg mine is ca 540 km from ESS, close to second osc. max.
The ESS n beam, with the Garpenberg Mine situated at a distance corresponding to the second oscillation maximum gives an excellent setup for exploiting a large CP-violation Signal
Kongsberg
L=480, D=1200m
9/9/2016
E. Wildner, CERN, NOW 2016

9. P(nm ne), three terms to distinguish dcp
Different scales
Atmospheric
Solar
Interference
9/9/2016
E. Wildner, CERN, NOW 2016

10. Interference term for different dCP
q13=8.7
S. Parke
9/9/2016
E. Wildner, CERN, NOW 2016

11. P(nm ne), three terms to distinguish dcp
Different scales
Atmospheric
Solar
Interference
9/9/2016
E. Wildner, CERN, NOW 2016

12. Choice of detector distance
Garpenberg (540 km)
9/9/2016
E. Wildner, CERN, NOW 2016

13. Systematic errors, default and optimistic
1 s:
Q %
sin22Q23 2%
sin22Q % 4% 3%
Unknown Hierarchy
The default is used in the simulations
E. Wildner, CERN, NOW 2016
9/9/2016

14. ESSnuSB as shape measurement experiment
2 years of data taking
Each histogram divided by the total number of events
Systematic normalization errors suppressed
Observed differences can be compared to statistical errors.
Only very modest discrimination between the different dCP values
No shape information
9/9/2016
E. Wildner, CERN, NOW 2016

15. ESSnuSB as counting experiment
Total number of ne and ne
2 years n
8 years n
Statistical errors about equal to the 7% systematic errors.
2.5 GeV (energy upgrade of ESS) would be more favorable
9/9/2016
E. Wildner, CERN, NOW 2016

16. ESSnuSB as ratio counting expt
M. Olvegård
Syst. and stat. errors balanced
Range of variation >-0.6
Good discrimination between
the different δCP values
9/9/2016
E. Wildner, CERN, NOW 2016

17. CP violation discovery and event statistics
71 %
69 %
65 %
56 %
Upper bound: NH
Lower bound: Hierarchy unknown
Nominal exposure: 8 years n+2 years n
Systematic errors: “SBOpt”
9/9/2016
E. Wildner, CERN, NOW 2016

18. Discovery of CP violation, comparison
Systematic errors: “SBDef.”
ESSnuSB360
ESSnuSB540
9/9/2016
E. Wildner, CERN, NOW 2016

19. ESSnuSB second maximum
Relative difference in counts at maximum between dcp p/2 and dcp 3p/2
Hyper-K first maximum
430/275 = 1.6
LBNE/DUNE first maximum
150/100 = 1.5
ESSnuSB second maximum
105/22 = 4.8
Sensitivity ~ 3 times higher
T. Ekelöf 19
9/9/2016

20. Proton Accumulator to shorten linac pulses
The ESS pulse is too long
Ohmic heating of horn current carrying surface, 350kA
Solution:
Shorten the pulse by accumulation in a ring
Challenge: protons per 2.86 ms pulse
accumulated intensity unprecedented
extraction of 1.32ms long proton pulses
Start with accumulation of ¼ of the intensity
in 4 stacked accumulators or
by making four shorter pulses of 2.86/4
Red: H-
Blue: H+
9/9/2016
E. Wildner, CERN, NOW 2016

21. Proton Accumulator: First design
Based on the optics of SNS, Oakridge
Simulations with ¼ * protons or more
Challenge:
injection of protons not efficient
H- injection needed
The ESS Linac needs some upgrades and studies for H- acceleration, (existing: studies and operation SNS & Linac4, studies of CERN SPL )
Target emitance goal: 100 (8.5 norm) mm mrad
Linac emittance 0.25 mm mrad
Injection painting to get a suitable distribution
“Simple formula” for first estimations:
No Space Charge problem:
DQ~0.25
However tracking is needed to confirm.
Collaboration CERN - Uppsala University
9/9/2016
E. Wildner, CERN, NOW 2016

22. Accumulator Results I
Preliminary layout design of H- beam transport lines on the site taking into account Lorentz stripping for max 2.5 GeV
Simulations are done at 2.0 GeV for the time being
Space charge challenges and instabilities are more important at low energy
Design of an accumulator ring and optics
Calculation of Foil Stripping Injection of H- (emittances and foil temperatures)
Temperatures not higher than what can be accepted (from presently running experiments)
However we know from SNS opertation that foils need attention
Simulations with modern multiparticle tracking codes to evaluate emittances and beam sizes
Space charge is not a show stopper
Emittances growth (bench marked with simpler code) but this can be handled
Good tune settings and best painting schemes will be calculated to minimize the space charge effects
What next:
Optics tuning
Injection optimization
Collimation
Magnet choice
Instability calculations, collective effects
9/9/2016
E. Wildner, CERN, NOW 2016

23. Accumulator Results II
¼ of total intensity in one ring
Goal: 100 mm mrad (norm)
Optimize optics
Space Charge on/off
M. Olvegård
9/9/2016
E. Wildner, CERN, NOW 2016

24. Previous Expertise ESSνSB
BENE ( )
ISS ( )
EUROν ( )
LAGUNA ( )
LAGUNA-LBNO ( )
SNS (USA)
E. Baussan, J. Bielski, C. Bobeth et al., “Neutrino super beam based on a superconducting proton linac,” Physical Review Special Topics, Accelerators and Beams, vol. 17, no. 3, Article ID , 26 pages, 2014.
NOW 2014, 10/9
E. Wildner, CERN

25. Information and references used for this presentation can be found in:
The Opportunity Offered by the ESSnuSB Project to Exploit the Larger Leptonic CP Violation Signal at the Second Oscillation Maximum and the Requirements of This Project on the ESS Accelerator Complex
E. Wildner,1 E. Baussan,2 M. Blennow,3 M. Bogomilov,4 A. Burgman,5 E. Bouquerel,2 C. Carlile,6 J. Cederkäll,5 P. Christiansen,5 P. Cupial,7 H. Danared,8 M. Dracos,2 T. Ekelöf,6 M. Eshraqi,8 R. Hall-Wilton,8 J.-P. Koutchouk,1,6 M. Lindroos,8 M. Martini,1 R. Matev,4 D. McGinnis,8 R. Miyamoto,8 T. Ohlsson,3 H. Öhman,6 M. Olvegård,6 R. Ruber,6 H. Schönauer,1 J. Y. Tang,9 R. Tsenov,4 G. Vankova-Kirilova,4 and N. Vassilopoulos9
,,CERN, 1211 Geneva 23, Switzerland2I
PHC, Universite´ de Strasbourg, CNRS/IN2P3, Strasbourg, France3
Department of Theoretical Physics, School of Engineering Sciences, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm, Sweden
4Department of Atomic Physics, St. Kliment Ohridski University of Sofia, 1164 Sofia, Bulgaria
5Department of Physics, Lund University, P.O. Box 118, Lund, Sweden
6Department of Physics and Astronomy, Uppsala University, P.O. Box 516, Uppsala, Sweden 7
AGH University of Science and Technology, Aleja Mickiewicza 30, Krakow, Poland 8
European Spallation Source, ESS ERIC, P.O. Box 176, Lund, Sweden
Institute of High Energy Physics, CAS, Beijing , China
Accepted for publication
Hindawi Publishing Corporation Advances in High Energy Physics Article ID
9/9/2016
E. Wildner, CERN, NOW 2016

26. ESS Neutrino Super Beam Collaboration
arXiv:
14 participating institutes from 10 different countries,
among them ESS and CERN
NOW 2014, 10/9

27. CERN-ACC-NOTE
9/9/2016
E. Wildner, CERN, NOW 2016

28. Support and Funding
ESSnuSB is supported by the Swedish Government, ESS and the Mine Company and the local Authorities.
An EU COST network application for ESSuSB was accepted : ”….The present project is unique in Europe and is building on a number of previous European projects. For the time being only two other similar projects exist, in the USA and in Japan.
The project is not only complementary to the projects in the USA and Japan but also competitive….” ESSnuSB applications submitted to the Swedish SRC and to the European Economic Growth Foundation.
Submission of a EU Design Study application is planned for autumn Funding of the Design Study remains a critical item.
9/9/2016
E. Wildner, CERN, NOW 2016

29. Diversity for the future?
nuSTORM
~1010 m/pulse in 200 < P(MeV/c) < 500
(if 1021 p/5years → 4.32x1017 μ/year)
ESSνSB
Input beam for future 6D m cooling experiments
muons/proton
~1012 m/pulse in 200 < P(MeV/c) < 500 (for 1 m2)
(2.6x1020 μ/year, at the level of the beam dump)
22 Nov. 2013
M. Dracos
E (GeV)

30. Summary
The ESSnuSB - has excellent and competitive physics potential for CP violation studies, - takes advantage of the ESS spallation accelerator, already financed and under construction, - has support (mine, ESS, Swedish government, Swedish authorities…) - has a strong group of 11 institutes that will bring the project up to a Design Report, - profits from earlier developments for the EUROnu SPL superbeam, including the target station and the far detector, - has ongoing development on accumulator, beamlines, and near detector… - is hoping/waiting for funding agencies to answer positively
Thank you !
9/9/2016
E. Wildner, CERN, NOW 2016

31. When and to what price ?
Total price of ESSnuSB including the detector is 1.2 BEUR:
100 MEUR linac
200 MEUR accumulator
200 MEUR target station
700 MEUR the far detector
If the CDR is ready in 2018, we could start construction when the neutron facility is ready, i.e., The construction will last up to when we will be able to start data taking.
If LBNE starts earlier (e.g ), in one or two years ESSnuSB will accumulate more protons on the target than LBNE.
NOW 2014, 10/9
E. Wildner, CERN

32. ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University
Supported by the owner of the mine
and by the local authorities
In a memorandum of Understanding the owner of the Garpenberg Mine, Boliden AB, authorizes ESSnuSB to access and investigate the mine and to consult with the personnel.
Discussions with the Chair of the Dalarna Region and the Mayor of the local commune:
great local enthusiasm for having the detector located in the Garpenberg mine.
Garpenberg
Mine
Dalahäst
Mascot of
Dalarna
ENUBET meeting in Padova 23 June Tord Ekelöf Uppsala University

33. Support by ESS
ESS CEO Jim Yeck : ESS management agrees to provide information and general support for the ESSnuSB collaboration’s ongoing studies.” Collaboration on preparations during linac build-up of power up-grade: power upgrades of tetrodes and modulators, keeping site areas for accumulator, target with decay tunnel and near detector free from other use A Workshop on “Upgrading Existing High Power Proton Linacs” 8-9 November 2016 at ESS in Lund The study of the upgrade of the ESS linac has an interest for several applications in addition to that which ESSnuSB represents like spallation neutrons, ADS, transmutation of nuclear waste, nuSTORM, Neutrino Factory, Muon Collider…
9/9/2016
E. Wildner, CERN, NOW 2016

34. The Swedish Government
During the two last years we have had three meetings with the Director General of Research at the Swedish Ministry of Research and Education to report on the progress in the planning of ESSnuSB. On 15 April 2015, State Secretary at the Ministry of Research: ESSnuSB project to the agenda of the Swedish government. The Scientific Councellor Mats Engström at the Embassy of Sweden in Japan was present in the The Third International Meeting for Large Neutrino Infrastructures maj 2016 in Tsukuba, including the closed agency meeting there, with the mission to report back to the Swedish Government.
ENUBET meeting in Padova 23 June Tord Ekelöf Uppsala University

35. ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University
Preparing the ESS linac for operation at
10 MW/8% duty cycle/28 Hz
For the medium-beta elliptical-cavity part
ESS is planning to use tetrodes. Thales
has developed a new screen grid with
graded wire thickness such that the
heating is evenly distributed over the
hight of the screen grid, thereby making
operation at 10 % duty cycle possible.
For the warm low-energy part of the
ESS linac and the medium energy
Elliptical-cavities part, ESS is planning to use modulators of the modular klystron modulator type which can be run at 28 Hz at double power by adding a capacitor charger-unit at the input. For the high energy elliptical Cavities IOTs will be used which by design can operate CW.
ENUBET meeting in Padova 23 June Tord Ekelöf Uppsala University

36. ENUBET meeting in Padova 23 June 2016 Tord Ekelöf Uppsala University
FREIA
The picture shows the cryostat and test bunker at the FREIA Lab in Uppsala where a first prototype of the ESS 352 MHz spoke accelerating cavity is currently under test at 14 Hz and later on will be tested at 28 Hz. Modulators for the high beta part of the linac will also be tested at 28 Hz.
ENUBET meeting in Padova 23 June Tord Ekelöf Uppsala University