1. Studies of Helium proportional counters response on fast neutrons, at NCSR “Demokritos” M. Zamani, M. Manolopoulou, S. Stoulos, M. Fragopoulou School of Physics, Faculty of Sciences Aristotle University of Thessaloniki Thessaloniki, Hellas

2. ARISTOTLE UNIVERSITY OF THESSALONIKI Objectives Optimization of operation parameters of the counters Optimization of operation parameters of the counters Determination of counter response Determination of counter response Application: Measurement and analysis of neutron spectra emitted from the spallation source “Energy plus Transmutation" Application: Measurement and analysis of neutron spectra emitted from the spallation source “Energy plus Transmutation"

3. ARISTOTLE UNIVERSITY OF THESSALONIKI Helium counters characteristics Pressure [Atm] GasmixtureLength[cm] Diameter [cm] He-36 3 He 65% Kr 33% Kr 33% CO 2 2% 155 He-418 4 He 99% CO 2 1% 605

4. ARISTOTLE UNIVERSITY OF THESSALONIKI Irradiations at the Institute of Nuclear Physics, NCSR Demokritos Proton Beam: 2.0 – 5.0 MeV Proton Beam: 2.0 – 5.0 MeV 7 Li(p,n) 7 Be neutron energy: 0.23 – 3.3 MeV Deuteron Beam: 1.4 – 7.8 MeV Deuteron Beam: 1.4 – 7.8 MeV 2 H(d,n) 3 He neutron energy: 3.7 – 10.7 MeV 3 H(d,n) 4 He neutron energy: 17.5 – 20.5 MeV

5. ARISTOTLE UNIVERSITY OF THESSALONIKI He-3 counter spectra Full energy peak 3 He(n,p) 3 H Recoil peak 3 He(n,elastic) 3 He(n,d) 2 H Thermal – epithermal peak (764 keV)

6. ARISTOTLE UNIVERSITY OF THESSALONIKI He-4 counter spectra 4 He(n,elastic)

7. ARISTOTLE UNIVERSITY OF THESSALONIKI Operational characteristics of He-3 and He-4 counters

8. ARISTOTLE UNIVERSITY OF THESSALONIKI “Energy plus Transmutation” setup Pb target: Diameter 8.4 cm, Length 48 cm Natural Uranium ≈206 kg NUCLOTRON accelerator, Laboratory NUCLOTRON accelerator, Laboratory of High Energies, Dubna - JINR of High Energies, Dubna - JINR

9. ARISTOTLE UNIVERSITY OF THESSALONIKI Neutron energy distribution calculated by DCM-DEM code Proton beam: 1 GeV

10. ARISTOTLE UNIVERSITY OF THESSALONIKI Irradiation of “Energy plus Transmutation” setup with Deuterons 1.6 GeV

11. ARISTOTLE UNIVERSITY OF THESSALONIKI Neutron energy distribution (preliminary results)

12. ARISTOTLE UNIVERSITY OF THESSALONIKI Future plans Calibration of neutron dosimeter systems based on SSNT detectors. Calibration of neutron dosimeter systems based on SSNT detectors. Study of proton track geometrical parameters on SSNT detectors for application in neutron spectroscopy. Study of proton track geometrical parameters on SSNT detectors for application in neutron spectroscopy. Fast neutron dosimetry with MOSFET. Fast neutron dosimetry with MOSFET. Cross section of (α,n) and (p,n) reactions in the energy region of several MeV. Cross section of (α,n) and (p,n) reactions in the energy region of several MeV.