1 Línea de neutrones en el CNA: HISPANoS (HISPAlis NeutrOn Source)PhD of Physics Sciences and Tecnologies. Directors: Javier Praena, Joaquín Gómez, José M. Espino. PhD student: Miguel Macías

2 Outline Context Motivations CNA as neutron facility (continuous beam)Tandem description Experiments (n_meV – MeV) CNA as neutron time-of-flight facility Upgrade description First tests TOF tecnique

3 Context No existen fuentes de neutrones basadas en acelerador en España. Existe una comunidad neutrónica española bastante amplia: CERN: spallation source, 20 GeV proton beam on Pb. Grenoble: the most powerful nuclear reactor for research. : línea de neutrones en el Tandem para irradiación y activación (solo disponemos de haz continuo), aplicaciones a astrofísica, física médica, daño en circuitos y es de especial interés la colaboración y atracción de otros grupos españoles y extranjeros al CNA para la realización de experimentos: UABarcelona, UIBaleares, US-Hospital Macarena, LNFrascati, LNLegnaro, UGR. 2014/2015: CNA es financiado (Infraestructuras) para la instalación de un sistema de pulsación y compresión temporal del haz del Tandem para el desarrollo de una línea de neutrones por tiempo de vuelo que permitirá la medida de espectros neutrónicos y secciones eficaces diferenciales.

4 Motivations: Different applications depending on the neutron beamNeutron beams (TOF or CW) Astrophysics (sr-process) Nuclear Tech. (criticality, heat, waste product., fusion) Medical Phys. Basic Nucl. Phys. (g strength funct., level densities, fiss. dynamics) Detector tech. Neutron production tech. HiSPANoS can deliver neutron beams that encompasses all these fields both in continuous (CW) and pulsed/bunched (TOF) mode . But TOF opens much more possibilities.

5 Why TOF and Integral measurements? Nuclear DataMCNP5, MCNPX, PHITS, FLUKA… GNASH, TALYS, INCL, CEM… TIME-OF-FLIGHT CONTINUOUS BEAM

6 CNA as neutron facility: TANDEM acceleratorAlphatross Pelletron 3MV Analyzing magnet Analyzing magnet Duoplamatron SNICS Switching magnet Valve Slits Faraday cup Beam Profile Monitor Steerers Quadrupole -3MV de diferencia de potencial es lo máximo que alcanza el acelerador -Primer tramo: E = q*delta V -Segundo tramo: E = n*delta V Energía total es: E= E source+(1+n)*delta V 𝐸= 𝐸 𝐼.𝑆. + (n+1) ΔV

7 What have we done since 2009 at HisPANoS?We have performed a radioprotection study by means of MNCPX simulations in order to check the possible activation or damage of the other beam lines and instruments. We have developed a system for neutron motorization based on the dosimetry history of the produced neutrons and the current history of the charge particle beam on the neutron target production. We have developed a system (HPGe) for neutron flux determination based on the activation of foils of elements with well-known cross-section and the Be7 production. We have carried out experiments that cover a large energy range:

8 Epithermal neutrons (keV): 7Li(p,n) reactionFor the first time, stellar neutron spectrum at kT=30 keV is generated and we do at CNA. Maxwellian-30keV is most important stellar temperature for nucleosynthesis and it is used as reference, therefore the MACS can be directly measurement by activation. J. Praena et al., NIM A, (2013) J. Praena et al., NDS, (2014). P. Jiménez et al., PoS (NIC XIII) 057 (2015). The neutron capture on Tb159 may affect the production of other species as Dy, Ho during the nucleosynthesis in AGB stars. Especially during the radiative C-13 pocket. The impact of the measured Tb(n,g) MACS was studied in C-13 pocket conditions, 3Mo star, Z=0.01. The variation of the MACS only affects the Tb production.

9 Thermal neutrons (meV-eV): Li(p,n)+moderationAt CNA, we generate well-characterized neutron spectrum with the 7Li(p,n) reaction at Ep=1912 keV. Then these neutrons are moderated to a thermal energy distribution. Thermal neutron detector to be used in radiotherapy halls for the study of the development of secondary tumour in LINAC for photon production. L. Irazola et al., Applied Radiation and Isotopes 107 (2016) J. Praena et al, Rad and Onc. vol 115, Supplement 1, Page S735

10 Fast neutrons: D(d,n) up to En=8 MeVAt CNA, we generate fast neutron spectra at different energies by means of the d-d reaction. At present the neutron energy is determined by the well-known reaction kinematics. Neutron flux can be determined with the activation of Al foils. SEU and MBU (Multiple Bit upset) Single Event Upset has been studied for the SRAMs developed in U. Islas Baleares. Work in progress. TiD2 target

11 CNA as neutron time-of-flight facilityA committe is following up the project: CIEMAT, IFIC, USC, UPB, US, UGR and CNA. Santiago Comp Barcelona Madrid Valencia Granada At present, in Europe, there is no a time-of-flight facility available for external users. Only GELINA (electrons on U) with TOF from 10 to 200 m. N_TOF collaboration at CERN, spallation source.

12 Upgrade

13 New Elements 3 MV PELLETRON ION SOURCE CHOPPER BUNCHER WIEN FILTER BPMSTEERERS SLITS XY FARADAY CUP PICK-UP

14 Chopper Freq. 62.5 kHz Width 62 ns DC & SWITCH HV -480 VION SOURCE CHOPPER BUNCHER 3 MV PELLETRON WIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP Freq kHz Width 62 ns DC & SWITCH HV -480 V

15 Buncher RF signal 8 MHz 3 MV PELLETRON ION SOURCE CHOPPER BUNCHERWIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP RF signal 8 MHz

16 Wien Filter 3 MV PELLETRON ION SOURCE CHOPPER BUNCHER WIEN FILTER BPMSTEERERS SLITS XY FARADAY CUP PICK-UP

17 Beam Profile Monitor 3 MV PELLETRON ION SOURCE CHOPPER BUNCHERWIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP

18 Beam Profile Monitor 3 MV PELLETRON 25 mm 30 mm ION SOURCE CHOPPERBUNCHER 3 MV PELLETRON WIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP 25 mm 30 mm

19 Steerers 3 MV PELLETRON ION SOURCE CHOPPER BUNCHER WIEN FILTER BPMSLITS XY FARADAY CUP PICK-UP

20 Slits XY 3 MV PELLETRON ION SOURCE CHOPPER BUNCHER WIEN FILTER BPMSTEERERS SLITS XY FARADAY CUP PICK-UP

21 Slits XY Protons 62.5 kHz Width 4-6 ns 3 MV PELLETRON ION SOURCECHOPPER BUNCHER 3 MV PELLETRON WIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP Protons 62.5 kHz Width 4-6 ns

22 Faraday Cup Protons ~ 63 nA 3 MV PELLETRON ION SOURCECHOPPER BUNCHER 3 MV PELLETRON WIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP Protons ~ 63 nA

23 Pick-Up Capacitive Ring-shaped L 20mm D 35mm 3 MV PELLETRON ION SOURCECHOPPER BUNCHER 3 MV PELLETRON WIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP Capacitive Ring-shaped L 20mm D 35mm

24 Pick-Up Protons 62.5 kHz Width 4 ns 𝑁𝑜𝑖𝑠𝑒 𝑠𝑖𝑔𝑛𝑎𝑙 < 0.5%ION SOURCE CHOPPER BUNCHER 3 MV PELLETRON WIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP Protons 62.5 kHz Width 4 ns 𝑁𝑜𝑖𝑠𝑒 𝑠𝑖𝑔𝑛𝑎𝑙 < 0.5%

25 NEC FFC tester 3 MV PELLETRON ION SOURCE CHOPPER BUNCHER WIEN FILTERBPM STEERERS SLITS XY FARADAY CUP PICK-UP NEC FFC

26 NEC FFC tester 62.5 kHz FWHM 1.8 ns 3 MV PELLETRON ION SOURCE CHOPPERBUNCHER 3 MV PELLETRON WIEN FILTER BPM STEERERS SLITS XY FARADAY CUP PICK-UP NEC FFC 62.5 kHz FWHM 1.8 ns

27 TOF tecnique

28 Gracias por su atención

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30 TOF tecnique

31 HiSPANoS TOF line: possible measurements.In the first phase, CNA group will be focused on the installation of the chopper/buncher system and background studies. In a second phase, CNA group will perform neutron spectrometry measurements in the epithermal energy range. We will setup an adquisition system for Li-glass detectors. In parallel, the most important objective of the CNA group is to collaborate to users and to provide suitable neutron beams for their measurements. HiSPANoS tof line will be (summer 2016) a very versatile facility since different neutron beams can be generated: d-d, Li(p,n), Be(p,n)… for thin and thick targets. Neutron spectra measurements Neutron capture cross-section measurements, (n,). Neutron-induced cross-section measurements, (n,f). Transmutation of nuclear waste, High temperatures reactors, Development of ADS systems, Th-U fuel cycle, U-Pu fuel cycle, Development of nuclear standards. Astrophysics. Neutron capture therapy.

32 HiSPANoS TOF & n_TOF-CERN: comparison.NEUTRON FLUX n/(cm2·s) HiSPANoS TOF 7Li(p,n) Ep=2,5 MeV 0,5m n_TOF EAR-1 (188m) n_TOF EAR-2 (20m) Energy interval (no collimation) 1 keV 100 keV 7·104 1,2·105 2,6·106 keV (HiSPANoS) 1 MeV (n_TOF) 5·103 4,2·105 7,3·106 E/E HiSPANoS (1ns - 0.5m) (1ns - 1m) n_TOF EAR-1 (6ns - 188m) n_TOF EAR-2 (6ns - 20m) Energy interval 1 keV 8,8·10-4 4,4·10-4 5,4·10-4 8,5·10-3 1 MeV 2,8·10-2 1,4·10-2 3,6·10-3 4,1·10-2 20 uA * 0.25 (8 MHz) *0.075 (500kHz) *0,9 (Tank Transmission) = kHz.

33 References J. G. Lopez et al., CNA: The first accelerator-based iba facility in Spain, Nuclear Instruments and Methods in Physics Research B (2000) T. Fowler et al., A theory on obtaining short bursts of ions from a beam of ions, Nuclear Instruments and Methods 7 (3) (1960) C. D. Moak et al., Nanosecond pulsing for van de graaff accelerators, Review of Scientic Instruments 35 (6) (1964) NEC. URL

34 HiSPANoS tof line: proton current comparisonThe less favorable case in terms of current (therefore neutron flux) will be an experiment at 500 kHz. As conservative example, we consider 20 uA at the source (NEC claims that SNICS-II source can work at 𝛍A during a day without problems): 20 uA*0.25(8 MHz)*0.075(500kHz)*0,9(Tank Transmission) = kHz Nowadays: kHz For comparison, the other facilities in Europe of the same characteristics: - JRC-IRMM (Belgium, EU)  kHz (recently decommisioned) - LNL-INFN (Padova, Italy)  kHz. - PTB (Germany)  kHz. (VdG was turned-off 2 years ago) - AMANDE (France)  Neutron fluence seems to be lower for Li(p,n), no external users.

35 Summary Motivations. Accelerator-based neutron sources: European and national framework. CNA as neutron facility from : continuous beam encompassing a large energy range and applications. CNA as neutron time-of-flight facility: 2017. Description of the CNA chopper/buncher for pulsing and time compression of the charge particle beam. Description of the CNA tof line. TOF measurements.