IRRADIATION EXPERIMENTS & FACILITIES AT BNL: BLIP & NSLS II

Peter Wanderer Superconducting Magnet Division, BNL WAMSDO – November 14, 2011

Brookhaven Linac Isotope Producer (BLIP)

    Schedule: ~ 6 months/year (during RHIC operation) Principal task: isotope production for medical etc. use (proton beam, 117 MeV).

Simultaneous irradiation and isotope production by increasing beam energy, placing irradiation target ahead of isotope production target • 117 Mev → 140, 160, 180, 202 MeV • Irradiation at room temperature Alternative: irradiation target

behind

isotope target, for irradiation by neutrons and scattered protons.

14/11/11 WAMSDO 2

Proton Beam Profile

90 mm 60 50 40 30 20 10 0 0 10 20

"A" "B" "C"

30 40 50 distance, mm 60 70 80 90 Sample The BLIP proton beam cross section deduced from a gamma scan of the activation foil irradiated with the samples. The grid is in mm.

The position of the three 1 cm segments in the beam cross section Section B sees a proton flux varying by less than ± 5% 14/11/11 WAMSDO 3

More BLIP info

    Target holder interior dimensions ~ 100 mm wide, 100 mm high, 75 mm deep.

Two target holders per assembly.

Target assembly immersed in water for cooling (flow: 200 liters per minute).

Current user: LBNE – materials for Project X.

• Long Baseline Neutrino Experiment – Abandoned gold mine northwest of Fermilab (DUSEL) • Measurements (yield strength, stress, CTE) in hot cell at BNL 14/11/11 WAMSDO 4

Basket mounts 14/11/11 WAMSDO Added .437” of material to this surface Windows machined integral to box Window & basket mounts moved up .437” relative to box mounts for improved beam alignment.

5

Windows machined integral to box 14/11/11 WAMSDO 6

Sample and Irradiation Details of 4 mm wide YBCO conductor

 7 cm long samples were mounted on five aluminum frames and inserted into the water filled target tank of the

Brookhaven Linac Isotope Producer (BLIP).

 The irradiation was done at

142 MeV

with a beam current of 40 μA, and different levels of proton flux were achieved by progressively removing the aluminum frames after specific times to give 2.5, 25, 50, 75, and 100 μA-hrs of irradiation.  100 μA-hrs is equivalent to a fluence of 3.4x10

17 cm -2 14/11/11 WAMSDO 7

Experiment

      Three 1cm sections of each conductor are measured.

YBCO samples are irradiated at the Brookhaven Linac Isotope Producer (BLIP) (G.Greene) Levels of proton fluence are 2.5, 25, 100 mA hrs.

B is positioned to be at the center of the beam.

Open cryostat. Samples are directly cooled by LN2.

Magnetic field (0.25T, 0.5T,0.75T, 1.0T and 1.25T) are provided by a non-superconducting magnet. I HTS sample is under the G-10 cover Voltage taps Angle=0: The normal to the tape plane is parallel to the external magnetic field courtesy G.Greene and B.Sampson

Rel.dose=25

  In actual FRIB system, estimated rel.dose would be ~10. rel.dose=25 is close to the actual dose.

I c of rel.dose=25 was expected to be between I c rel.dose=100(highest) and rel.dose=2.5 (lowest).

However… ASC

Angular dependence of ASC sample on Ic at various dose levels at 1T

of SuperPower 30 25 20 15 10 5 0 0

rel.dose=25 rel.dose=2.5

rel.dose=100

30 60 90 120 150 180 210 240 270 300 330 360

angle(deg)

 As field increases, Ic decreases monotonically for any radiated samples.

  Rel.dose=25 gives slightly higher Ic than rel.dose=2.5 in some magnetic fields. This effect is clear in SuperPower sample but not in ASC sample.

I

c

vs magnetic field

1.2

1 0.8

0.6

0.4

25 2.5

0.2

0 0 100 ASC 0.5

1 magnetic field (T) ASC 0 deg 1.5

1.2

1 0.8

0.6

0.4

25 0.2

0 0 100 2.5

0.5

1 magnetic field(T) ASC 90 deg 1.5

SuperPower 1.2

1 0.8

0.6

0.4

0.2

0 100 0 2.5

25 SP 0 deg 0.5

magnetic field (T) 1 1.5

1.2

1 0.8

0.6

0.4

25 2.5

0.2

0 0 100 0.5

magnetic field (T) 1 SP 90 deg 1.5

Measured I c at 77K, self field

Critical current (I c ) of samples was measured before and after irradiation at 77 K, self field.

I c of all samples before radiation was ~100 A.

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

0 Radiation Damage Studies on YBCO by 142 MeV Protons by G. Greene and W. Sampson at BNL (2007-2008) I c Measurements at 77 K, self field

SuperPower Sample#1 SuperPower Sample#2 SuperPower Average ASC Sample#1 ASC Sample#2 ASC Average I c of all original (before irradiation) was ~100 Amp 100 m A.hr dose is ~ 3.4 X 10 17 protons/cm 2 (current and dose scale linearly)

25 50 75 Radiation Dose (

m

A.Hours) 100

Ramesh Gupta, BNL 3/2008

125

As radiation dose increases, I c decreases monotonically for both ASC and SuperPower YBCO samples (courtesy G. Greene and W. Sampson) 14/11/11 WAMSDO 11

YBCO and Nb

3

Sn

   YBCO (High Temperature Superconductor) • • Target cooled off to “no detectable radioactivity”. Had surface contamination. → Test in dewar in “clean” area, behind “caution” tape and sign (i.e., not in hot cell) Annealing varied with dose (low dose → no anneal) • Not production material.

Nb 3 Sn – ITER material • Annealing at room temperature not significant.

Nb – “pure Nb has 600 ppm Ta – long-lived radioisotopes after irradiation.

14/11/11 WAMSDO 12

PROPOSED ENDSTATION FOR NEW BNL LIGHT SOURCE, NSLS II

    Endstation for radioactive materials • • 30 – 80 keV monochromatic photons Beam diameter: 10 μm • Techniques: Diffraction, imaging Endstation for real-time, in situ studies w. photons • 1 MeV tandem for heavy ions • • • 200 kV accelerator for H, He Ion beam diameter: μm to mm Time resolution: μs to ms Supporting infrastructure Presentation to Advisory Committee 17 Nov.

14/11/11 WAMSDO 13

Credits

   BLIP: L. Mausner, A. Ghosh YBCO measurements: R. Gupta, G. Greene, W. Sampson, Y. Shiroyanagi NSLS II: A. Ghosh, L. Ecker 14/11/11 WAMSDO 14

Real time and in-situ studies of Materials in a Radiation Environment (MRE)

• • • •

MRE at NSLS II

Ion accelerators for in situ experiments of radiation effects and mesoscale microstructural changes due to radiation Separate endstation for radioactive materials Will enable studies of new materials for reactors, nuclear fuels and structural materials in high radiation environments Data for verification of computer simulations, material • • performance during off-nominal conditions, and licensing • •

Examples of Science Areas & Impact

NUCLEAR STRUCTURAL MATERIALS: Role of interfaces in radiation resistant materials NUCLEAR FUELS: Characterization of spent fuel, metal fuels, and new synthesis routes for oxide fuels NATIONAL SECURITY: material characterization for nuclear forensics SEMICONDUCTOR FABRICATION: Understand the effect of doping induced defects on semiconductor performance

Displacement Cascade Near a Grain Boundary

Bai, et al. Science, 2010

Beamline Capabilities Techniques:

Diffraction, Imaging, Spectroscopy

Source:

Damping or superconducting wiggler

Energy range:

10-90 keV

Time resolution

: msec µsec

Beam Size

: > 1 µm