1. n_ToF dump as a facility for Neutron Radiation Testing11
n_ToF dump as a facility for
Neutron Radiation Testing
Francisco Rogelio Palomo,
Miguel A. Cortés-Giraldo,
José Manuel Quesada ,
University of Sevilla 1

2. 22
There is a clear and growing need of neutron facilities in Europe for:
Testing of electronic/optoelectronic devices
In general neutron measurements
BUT few facilities are available at present: 2

3. ESA/ESTEC (Noordjvik, Holland)33
ESA/ESTEC (Noordjvik, Holland)
CASE : Californium-252 Assessment of Single-event Effects
Activity: μCi
1 μCi emits 4.4x103 neutrons/second with an average energy of 2.3 MeV. 3

4. 44
Uppsala University/The Svedberg Laboratory (TLS) Cyclotron (p) from ~20 to 175 MeV
Two main facilities:
ANITA: Atmospheric-like Neutrons from thIck Target
QMN: Quasi Mono-energetic Neutron beam facility 4

5. 55 The Svedberg Laboratory: radiation testing facilities
neutron spectrum: atmospheric-like up to 150 MeV from spallation
neutron flux >10 MeV: ~ 106 cm-2 s-1
QME: Quasi mono-energetic neutron beam facility
ANITA :Atmospheric-like Neutrons from thIck TArget
Neutron production reaction: 7Li(p,n)
Peak neutron energy: MeV
Standard neutron fields: 11, 22, 47, 94, 110, 143, 174 MeV
Peak neutron flux: 1· ·105 neutron cm-2 s-1 5

6. 66 n_TOF neutron beam It has unrivalled characteristics:
It is a high quality beam, extremely clean of charged particles after ~185m of TOF tube, sweeping magnet and collimators
It has a white spectrum covering an extremely wide energy region, from thermal to GeV range
Slightly disrupted by main experiments (expected: to be checked) 6

7. n_TOF neutron beam
Gamma flash :
1) Is not a serious problem for studies of neutron radiation testing (short duration)
2) Anyway the use of a W filter could greatly reduce its effect

8. PROPOSAL : 88 BUT: The remnant beam is directly sent to the dump,
MOREOVER:
Dump area is plenty of room for additional experiments in parasitic mode.
BUT:
The remnant beam is directly sent to the dump,
without any further usage.
PROPOSAL :
To use n_ToF dump as a facility for neutron radiation testing
No disturbance of the main experimental program is foreseen.
No additional infrastructure is requested.
ADVANTAGES: 8

9. 99 Details of the proposal: Actions to be taken (1)
Characterization of the beam at the dump area
Spectrum
Profile
Usage of Medipix detectors is foreseen (experience after last summer measurements will
be highly valuable)
Micromegas?
Temperature monitoring (within 0.1ºC)
Re-usage of (already in place) FIC2 chamber ( measurements in vacuum)
193m from target beam Ø~6cm 9

10. Details of the proposal: Actions to be taken (2)
10 cm
3 cm
Optimal positioning if inside the central hole of polyethilene block: (measurements in air)
198 m from target , beam Ø~7.6 cm

11. Case study: Flip-flop n_TOF
Using GEANT4, we generate a neutron beam with n_TOF spectra
Target is a flip-flop, with dimensions and structure taken from a real flip-flop in a well known technology (2 metals, 0.5 micron, AMSC5)
Lessons learned in the n_TOF experiments (parasitic mode) will be used for the design of a new neutron source at CNA.
Overview 11

12. Case study: Flip-flop n_TOF
Master-slave flip-flop (AMIS C5) and clock buffer, comprised of a total of 28 transistors, used in heavy-ion experiment. 12

13. Case study: Flip-flop n_TOF
Flip-flop schematic is part of a target chip, modelled with FASTRAD for virtual irradiation with GEANT4. 13

14. Case study: Flip-flop n_TOF
Monte Carlo simulations calculate energy deposition in gate oxides to evaluate TID, and in channels to estimate NIEL. 14

15. Case study: Flip-flop n_TOF 15

16. Case study: Flip-flop n_TOF
Results compare well with simulations for a future neutron source at CNA (cyclotron deuterons on Be) 16

17. Case study: Flip-flop n_TOF
Conclusions
Minimal interference with the n_TOF main experiments.
Calibrations for the new CNA neutron source: n_TOF spectra is almost without gamma radiation.
Results compare well with simulations for a future neutron source at CNA (cyclotron deuterons on Be) 17