Irradiation facilities at the INFN National Laboratory of Legnaro A. Candelori Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica, Padova 2/4/2004
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.
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).
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 28.18 1 1 4390 0.02 0.07 10-4 7 Li 56.18 3 3 378 0.37 2.07 10-4 11 B 80.68 4 5 195 1.01 6.07 10-4 12 C 94.68 5 6 171 1.49 8.06 10-4 16 O 108.68 6 7 109 2.85 16.1 10-4 19 F 122.68 7 8 99.3 3.67 21.3 10-4 28 Si 157.68 8 11 61.5 8.59 56.2 10-4 32 S 171.68 9 12 54.4 10.1 75.8 10-4 35 Cl 171.68 9 12 49.1 12.5 92.2 10-4 48 Ti 196. 18 10 14 39.3 19.8 177 10-4 51 V 196.18 10 14 37.1 21.4 203 10-4 58 Ni 220.68 11 16 33.7 28.4 284 10-4 63 Cu 220.68 11 16 33.0 30.5 342 10-4 74 Ge 231.18 11 17 31.8 35.1 455 10-4 79 Br 241.68 11 18 31.3 38.6 548 10-4 107 Ag 266.18 12 20 27.6 54.7 1132 10-4 127 I 276.68 12 21 27.9 61.8 1584 10-4 197 Au 275.68 13 26 23.4 81.7 4748 10-4
High flux (>10 8-10 9 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 0.6 0.6 cm 2. The figure is not drawn to scale.
Low flux ( 10 2-10 6 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.
Beam time allocation at SIRAD in 2002 January 2002- 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%
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
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 2-7 100 Monochromatic 5-10 Rev. Mod. Phys. (1956) 103-134 T(d,n) 4 He 2-7 100 Monochromatic 18-24 Rev. Mod. Phys. (1956) 103-134 7 Li(p,n) 7 Be 2-7 500 Monochromatic 0.2-5 NIM A 238 (1985) 443-452 9 Be(d,n) 10 B 2.6-7 300 Continuos 0.06-11.4 NIM A324 (1993) 239-246 9 Be(d,n) 10 B with moderator 2.6-7 300 Thermal <0.4 10-6 NIM A489 (2002) 347-369
W and Mo X-rays: Seifert Rp-149 Irradiation Facility Tube with W (7.4-12.06 kev L-lines) or Mo (17.4-19.6 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
W and Mo X-rays: emission spectra 1.0 17.4 kev Photons/(mA s mm 2 ) at 750 mm normalized to maximum 0.8 0.6 0.4 0.2 7.6-12.06 kev W Mo 19.6 kev W anode, 50kV, 0.1 mm Al filtration Mo anode 30 kv, 0.1 mm Mo filtration 0.0 0 5 10 15 20 25 30 35 40 45 50 Photon energy (kev)
W and Mo X-rays: radiation field dimensions Dose rate (rad(si)/s) 140 120 100 80 60 40 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) 20 0 140 120 100 80 60 40 20 20.6 mm -20-15 -10-5 0 5 10 15 20 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 0-20 -15-10 -5 0 5 10 15 20 Y position (mm)
60 Co γ-ray source Irradiation Facility: Panoramic Gammabeam model 150 A produced by Nordion Ltd (Canada) Photon energies: 1.165 MeV and 1.332 MeV Present activity: 2000 Ci ( 7.4 10 13 Bq) Point source for D>10 cm (D=10-300 cm) Dose rate: 8.33 rad (H 2 O)/s at D=20 cm (dose(h 2 O)/dose(Si)=0.9)
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 (>10 8-10 9 ions/cm 2 s) and low (10 2-10 6 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 17-20 kev) anode; dose rate: 120 rad(si)/s. - γ-rays: 60 Co with 7.5 rad(si)/s dose rate.