Irradiation facilities at the INFN National Laboratory of Legnaro

Transcription

1 Irradiation facilities at the INFN National Laboratory of Legnaro A. Candelori Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica, Padova 2/4/2004

2 OUTLINE The SIRAD irradiation facility at the TANDEM accelerator: - high energy protons and ions. The CN accelerator: - protons and neutrons. Total dose tests: - Tungsten (W) and Molybdenum (Mo) X-rays; - 60 Co γ-rays.

3 The SIRAD beam line (high energy protons and ions) TANDEM accelerator: - Van de Graaff type; - 15 MV maximum voltage; -two strippers; - servicing 3 experimental halls for nuclear and interdisciplinary Physics. Fig.1. Schematics of the 15 MV TANDEM Van de Graaff accelerator and of the SIRAD irradiation facility at the +70º beam line (left). A photograph of the SIRAD irradiation facility is also shown for completeness (right).

4 Ion beams available at SIRAD Ion species from 1 H (23-30 MeV) up to 197 Au (1.4 MeV/a.m.u.) LET from 0.02 MeV cm 2 /mg ( 1 H) up to 81.7 MeV cm 2 /mg ( 197 Au) Table I Characteristics of the typical ion beams available at the SIRAD irradiation facility for bulk damage and single event effects studies with the TANDEM operating at 14 MV with two strippers. Ion Energy q 1 q 2 Range in Si Surface LET in Si Surface NIEL in Si Species (MeV) (µm) (MeV cm 2 /mg) (MeV cm 2 /mg) 1 H Li B C O F Si S Cl Ti V Ni Cu Ge Br Ag I Au

5 High flux (> ions/cm 2 s) irradiation set-up on 5 5cm 2 Sample holder 3x3 Faraday cup battery 5x5 cm 2 aperture Ion or proton beam 5 cm Irradiation Chamber Device under test Fig. 2. The on-line beam monitoring for rastered proton and ion beams by the 3 3 battery of Faraday cups positioned behind the DUT: side view of the experimental setup. The aperture of each Faraday cup is cm 2. The figure is not drawn to scale.

6 Low flux ( ions/cm 2 s) irradiation set-up on 2 2cm 2 Ion beam 5x5 cm 2 aperture 5 cm Sample holder Geometric aperture 2x2 cm 2 Mobile diode board 5 cm 2 cm Irradiation chamber Fixed diodes Mobile diodes Devices for SEE tests Fixed diode board Fig.3. The on-line beam monitoring system for defocused beams by the fixed and mobile diodes: -left: side view of the experimental set-up; -right: front view (transverse to the beam) of the fixed and mobile diode boards. The mobile diodes are mounted on the sample holder with the DUT. The figure is not drawn to scale.

7 Beam time allocation at SIRAD in 2002 January December 2002 (624 hours) 5c) SEE in read-out electronics 20% Others 2% 1) Radiation effects in CMOS technologies 8% 2) Bulk damage in silicon detectors 7% 3) Secondary electron emission 12% 5b) SEE in FPGA 19% 5a) SEE in floating gate memories 6% 4) SEB and SEGR in power MOSFETs 26%

8 CN accelerator Characteristics: Van de Graaff type, 7 MV maximum voltage; Ion species: p ( 1 H); d ( 2 H); t ( 3 H); 4 He (single or double charge) and 15 N (double charge) Max energy: 7 MeV for single charged species;14 MeV for 4 He ++ ; 8 MeV for 15 N ++. T(d,n) 4 He 9 Be(d,n) 10 B with moderator D(d,n) 3 He 7 Li(p,n) 7 Be 9 Be(d,n) 10 B

9 CN accelerator: neutron beams Table II Neutron sources at the CN accelerator Formula E beam I max Spectra E neutrons at 0 Reference (MeV) (na) (MeV) D(d,n) 3 He Monochromatic 5-10 Rev. Mod. Phys. (1956) T(d,n) 4 He Monochromatic Rev. Mod. Phys. (1956) Li(p,n) 7 Be Monochromatic NIM A 238 (1985) Be(d,n) 10 B Continuos NIM A324 (1993) Be(d,n) 10 B with moderator Thermal < NIM A489 (2002)

10 W and Mo X-rays: Seifert Rp-149 Irradiation Facility Tube with W ( kev L-lines) or Mo ( kev K-lines) anode. Maximum tube voltage 60 kv. Maximum tube current 50 ma. X,Y (motorized) and Z (manual) axis for accurate position setting of the tube. X-ray tube Laser pointer Y axis motor Semi-automatic probestation Z Y X

11 W and Mo X-rays: emission spectra kev Photons/(mA s mm 2 ) at 750 mm normalized to maximum kev W Mo 19.6 kev W anode, 50kV, 0.1 mm Al filtration Mo anode 30 kv, 0.1 mm Mo filtration Photon energy (kev)

12 W and Mo X-rays: radiation field dimensions Dose rate (rad(si)/s) D=10 cm D=15 cm D=20 cm D=40 cm 13.9 mm 15.5 mm 16.1 mm Dose rate (rad(si)/s) mm X position (mm) D=10 cm D=15 cm D=20 cm D=40 cm 7.2 mm 9.2 mm 11.4 mm 19.4 mm Y position (mm)

13 60 Co γ-ray source Irradiation Facility: Panoramic Gammabeam model 150 A produced by Nordion Ltd (Canada) Photon energies: MeV and MeV Present activity: 2000 Ci ( Bq) Point source for D>10 cm (D= cm) Dose rate: 8.33 rad (H 2 O)/s at D=20 cm (dose(h 2 O)/dose(Si)=0.9)

14 Conclusions The SIRAD irradiation facility at the 15 MV TANDEM accelerator: - Ion species from 1 H (23-30 MeV) up to 197 Au (1.4 MeV/a.m.u.) - LET from 0.02 MeV cm 2 /mg up to 81.7 MeV cm 2 /mg - High (> ions/cm 2 s) and low ( ions/cm 2 s) flux set-up The CN accelerator: - Monochromatic spectra: D(d,n) 3 He, T(d,n) 4 He, 7 Li(p,n) 7 Be - Continuous spectra: 9 Be(d,n) 10 B - Thermal neutrons: 9 Be(d,n) 10 B with moderator Total dose tests: - X-rays: W (L-lines at 7-12 kev) and Mo (K-lines at kev) anode; dose rate: 120 rad(si)/s. - γ-rays: 60 Co with 7.5 rad(si)/s dose rate.