Irradiation tests at HZDR · 2016. 9. 29. · PowerPoint Presentation Author: Anna Ferrari Created...
Transcript of Irradiation tests at HZDR · 2016. 9. 29. · PowerPoint Presentation Author: Anna Ferrari Created...
Irradiation tests at HZDR Anna Ferrari, Stefan Müller
Member of the Helholtz Association 2 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
pELBE and nELBE beamlines at ELBE
(Electron Linear accelerator with high Brilliance and low Emittance)
National Center for High-Power Radiation Sources:
• Multiple secondary beams (neutrons, photons, positrons) & High-Power laser (PW) for
electron/ion acceleration
• nELBE: Neutron Time-of-Light Facility for Transmutation Studies and Nuclear Physics
measurements
• pELBE (EPOS) Photo-neutron sources: neutron production via photo-nuclear reactions
Ee ≤ 40 MeV Ie ≤ 1 mA
Micropulse
duration Dt < 10 ps
f = 13 MHz / 2n
nELBE EPOS
Neutron ToF hall
Gamma hall
e-
Member of the Helholtz Association 3 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
nELBE: the photo-neutron source
Radiator: 1.12 cm lead Channel in Mo, 0.5 mm thick
Electron beam power
up to 40 kW
Power density in the
neutron radiator up to
25 kW/cm3
Liquid lead circuit
for heat transport
Member of the Helholtz Association 4 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Electron
Energy
(MeV)
Neutron Yield [ n/e-]
(FLUKA sim.)
Source Strength [n/s]
@1 mA ( FLUKA sim.)
Photon Yield [ /e-]
(FLUKA sim.)
30 3.108 10-3 1.94 1013
4.14
Source strength and photon/neutron yield ratio
Problem: /n yield 103 !
Member of the Helholtz Association 5 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Liquid-lead
photo-neutron source
@ 1 m , 100A e- current and 30 MeV e- energy:
1.54 107 n cm-2 s-1
To accumulate 3·1011 n/cm2 only 5.4 h are needed
To suppress the gamma radiation
a local Pb shielding can be used, without
problematically losing neutron flux
Member of the Helholtz Association 6 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Use Pb shielding to lower the /n ratio
With 5 cm lead shielding the /n ratio goes down to 10 beyond the lead block
Photon fluence (n cm-2 per primary e-)
Neutron fluence (n cm-2 per primary e-)
Pb
e-
Member of the Helholtz Association 7 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
A better solution: the EPOS source
at positron extraction beamline pELBE
e-
positron extraction beamline
Bremsstrahlung/photoneutron
target: 1 cm W
Member of the Helholtz Association 8 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Geometry around the target
e-
Pb
Al
borated
polyethylene
1 cm W
Member of the Helholtz Association 9 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Radiation fields around the target: fluence rates
Photon fluence ( cm-2 per primary e-)
Proton fluence (p cm-2 per primary e-) Electron fluence (e- cm-2 per primary e-)
Neutron fluence (n cm-2 per primary e-)
Member of the Helholtz Association 10 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Radiation fields around the target: dose [H*(10)] rates
Neutron dose rate (mSv/h ) Photon dose rate (mSv/h )
Total dose rate (mSv/h )
Member of the Helholtz Association 11 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Irradiation position
Member of the Helholtz Association 12 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Fluence profiles at the irradiation position
Member of the Helholtz Association 13 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Dose profiles at the irradiation position
EPOS is an optimal neutron source for radiation damage studies
Member of the Helholtz Association 14 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
1 MeV-equivalent neutron spectra
The 2 plots refer to different irradiation positions of the SiPMs
Member of the Helholtz Association 15 MUSE Collaboration Meeting , Pisa, 28-30 September 2016 Anna Ferrari | Institute of Radiation Physics | www.hzdr.de
Planning the irradiation tests
2 options:
• Running in parasitic way -> we completely depend on the main user needs
• Asking for dedicated beamtime
Next deadline: November 1, 2016
for the beamtime 1 Jan 2017 – 30 Jun 2017