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Реактор ПИК и Европейский нейтронный ландшафт А.И. Иоффе Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Garching, Germany РНСИКС, 27-­‐31 октября 2014, Санкт-­‐Петербург 50 reactors and 8 spallaLon sources Main conLnuos source in Europe: ILL -­‐ Grenoble FRM-­‐II -­‐ Munich Orphée-­‐LLB – Saclay SINQ -­‐ PSI, Switzerland BERII – Berlin BNC -­‐ Budapest IRI DelM – The Netherlands NPL – Prague -­‐ Czech Republic WWRM – Gatchina, Russia +PIK (Gatchina, Russia) World: HFIR, NIST, ANSTO, Chalk River, China, Hanaro, Egypt, Serpong, Marocco, … SpallaLon sources (Europe): ISIS – Oxfordshire, UK JINR – Dubna, Russia +ESS – 2019 Sweden World: SNS – Oak Ridge – USA (2006) J-­‐PARC – Japan (2008) LANSCE – Los Alamos, USA + C-­‐SNS – China (?) European Landscape in 2020th : + first neutron at ESS + PIK in Russia -­‐ BER 2 (HZB, Berlin), -­‐ Orphée (LLB) ?, -­‐ PSI -­‐ ILL (2013-­‐2023; then jll when 203?) Thermal neutron flux, n/cm2s Neutron Sources: fluxes PIK European neutron instrument days = = (facility operajng days) x (number of operajonal instruments). In prac?ce days delivered to users will be 80-­‐85% of this value. UK NS Roadmap by R.McGreevy European neutron instrument days = = (facility operajng days) x (number of operajonal instruments). In prac?ce days delivered to users will be 80-­‐85% of this value. New landscape! UK NS Roadmap by R.McGreevy Developed last year; got full support of interna?onal reviewers in April (POF-­‐III), is a basis for the long-­‐term planning in BMBF Why pulsed (spallaLon) sources? •  Polijcs (ecology) •  Larger neutron output/MW •  Very significant gain in the instrumental intensity MonochromaLc and TOF instruments Time-­‐of-­‐flight (TOF) setup Chopper Simultaneous coverage of a wide Q-­‐range, however low intensity Monochromajc beam setup Monochromator Stepwise coverage of Q-­‐range, however high intensity MonochromaLc and TOF instruments Time-­‐of-­‐flight (TOF) setup Chopper Monochromator Simultaneous coverage of a wide Q-­‐range, but lower intensity: Flux Monochromajc beam setup Stepwise coverage of Q-­‐range, but higher intensity Chopper pulses Φ
τ T
τ
1
Φ pulse = Φ ≈ Φ
T
25
t TOF: wide simultaneous Q-­‐range 1
1
Single θ seung Si-15ASiO2-air.dat
STAP_sample result
50 counts
0.01
0.001
0.001
0.0001
1e-05
1e-05
0
λmax 0.05
Q λmin 0.1
θ0 1e-06
0
0.15
0.05
0.2
θmin Q θmax 0.1
λ0 Si-15ASiO2-air.dat
STAP_sample result
50 counts
0.1
0.2
Factor of about 25! 1
Si-15ASiO2-air.dat
STAP_sample result
50 counts
0.01
1
0.15
Si-15ASiO2-air.dat
STAP_sample result
50 counts
0.1
Intensity Intensity
Intensity 1
Single θ seung Si-15ASiO2-air.dat
STAP_sample result
50 counts
0.01
0.0001
1e-06
Muljple θ seungs 0.1
S(Q) 0.1
S(Q) Monochromajc: stepwise coverage 0.1
0.001
0.01
0.01
0.001
0.0001
0.001
0.0001
0.0001
1e-05
1e-05
1e-05
1e-06
0
λmax 0.05
Q λmin 0.1
θ0 0.15
1e-06
1e-06
0
0
0.05
0.05
0.2
θmin Q θmax 0.1
0.1
λ0 0.15
0.15
0.2
0.2
MonochromaLc and TOF instruments Time-­‐of-­‐flight (TOF) setup Chopper Monochromator Simultaneous coverage of a wide Q-­‐range, but lower intensity: Φ pulse =
Flux Monochromajc beam setup Chopper pulses τ
1
Φ≈ Φ
T
25
Φ
τ T
t Stepwise coverage of Q-­‐range, but higher intensity TOF at reactor instruments: significant intensity losses that wipes out the advantage of simultaneous coverage of a wide Q-­‐
range. ⇒  Even. MonochromaLc instruments at reactors vs. TOF at pulsed sources. Pulsed sources: the same average flux as at reactor source, but in peak structure Pulse from PS Flux Φ PS ≈ Φreactor
pulsed
Φreactor
=
Chopper pulses Φ PS
Φreactor
τ τ t T τ
Φreactor > Φreactor
T
Pulsed sources are gaining vs. chopper pulses from reactor beams. ESS vs. other spallaLon sources Average flux of ESS ≈ ILL •  Comparison of TOF and Mono instruments at reactor and SS. Source: ESS What ESS can give us? A TOF instrument at ILL vs. a TOF instrument at ESS If we will use the full ESS pulse, then: Φ D17 =
Flux Φ ILL ≈ Φ ESS
τ
1
Φ ESS Refl ≈ ⋅ Φ ESS Refl
T
25
Pulse ESS τ ESS = 2.8ms
Pulse D17 Φ ESS
Φ ILL
τ τ t T TESS = 72ms
Gain against ILL is about 25! Taking into account more modern neutron opjcs – 30-­‐40! Another gain: flat moderators a new moderator concept (F.Mezei, K.Batkov, A. Atynkbaev) Para-­‐H2 Higher brightness in verjcal plane h=3cm The gain factor is 3-­‐5 for cold neutrons and 1.5-­‐2 for thermal neutrons for instruments that using focusing opjcs (small samples) What ESS can give us? A TOF instrument at ILL vs. a TOF instrument at ESS If we will use the full ESS pulse, then: Flux Φ ILL ≈ Φ ESS
Φ D17 =
τ
1
Φ ESS Refl ≈ ⋅ Φ ESS Refl
T
25
Pulse ESS τ ESS = 2.8ms
Pulse D17 Φ ESS
Φ ILL
τ τ t T TESS = 72ms
Gain against ILL is about 25! Taking into account more modern neutron opjcs – 30-­‐40! Flat moderator – another factor 2.5-­‐3. thus, for instruments using focusing opjcs the gain vs. ILL will be about 100! Thus ESS will provide a huge flux gain w.r.t. most intense reactor sources. Will this result in quick and therefore a significantly larger number of experiments ? Example: a high-­‐intensity reflectometer at the ESS 1
1 Reflecjvity 10-­‐1
10-­‐2 Thin film growing in-­‐situ in steps of 280 ms (1cm2 sample) 10-­‐3 0.1
Polystyrene 300Å in 210ms 0.01
0.001
10-­‐4 0.0001
10-­‐5 1 frame of 210ms Polystyrene200A_on_Si_ref.dat
Polystyrene_200A result
50 counts
1e-05
0.12Å-­‐1 Kinejcs: YES Q 0
0.05
0.1
0.15
0.2
Standard reflectometry: NO Changes of temperature take tens of min Real gain is a possibility of studies of much smaller effects than today (very thin layers, low contrast, small samples, …). But total experiment dura?on will be about 1 week as today However, the number of instruments at the ESS is limited by only 16 (2022) and may rise to 22 instruments (2026). ESS instrument plan (tentajve) ILL – about 40 instruments, MLZ– about 35 instruments Ø  when they will be phased out -­‐ much less instruments than today Ø  Inevitable loss of European user base. Ø  Compact neutron sources (10 to be build in Japan – similar situajon) However, the number of instruments at the ESS is limited by only 16 (2022) and may rise to 22 instruments (2026). ESS instrument plan (tentajve) ILL – about 40 instruments, MLZ– about 35 instruments Ø  when they will be phased out -­‐ much less instruments than today Ø  Inevitable loss of European user base. Ø  Compact neutron sources (10 to be build in Japan – similar situajon) Ø  PIK! What PIK should be to play this important role? (biased point of view) -­‐ complimentary to ESS and able to take over a large user flow •  Outstanding instrumentajon: Ø  Instruments answering main trends in science; the science cases for ESS shows what users are expecjng. Ø  PIK instruments be{er than at ILL & MLZ, use experience from the ESS (cf. JCNS workshop in Tutzing) Ø  Much be{er use of reactor neutrons: be{er moderators, delivery systems, less background, larger solid angle, relaxing resolujon jll maximally possible. Ø  Implementajon of modern neutron technologies in neutron opjcs, detecjon, polarizajon analysis for be{er usage of sca{ered neutrons. •  modern methods of neutron data treatment, including visualizajon, graphic user interfaces, common data format and data treatment soMware •  Modern sample environment – reliable and on the brink of possible. What PIK should be to play this important role? (biased point of view) -­‐ complimentary to ESS and able to take over a large user flow •  Outstanding instrumentajon •  Muljdisciplinary, a{racjon of own non-­‐neutron users. Building complementarity to synchrotron facilijes, up to common user program. Not a compejjon, but cooperajon! •  Less accent on short-­‐term local interests – all user facilijes went through this and the outcome is clear: 20-­‐30% is a proper rajo to account for them. •  friendly user policy •  Inclusion of young scienjsts: they are the future of facilijy A great interest in Europe: pracjcally every serious scienjfic leader understands a great value of PIK to keep the neutron community (and therefore the neutron sources) alive in a long-­‐term. 
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