Proton Interrogation

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Proton Interrogation

Proposal 20081923

Steven Greene, P-25

2/5/2008

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Proposal 20081923: Short Range Proton Interrogation Co-Investigators• Chris Morris, P-25 (Principal Investigator)• Steve Greene, P-25• Fesseha Mariam, P-25• David Clark, P-22• Mark Makela, P-25• Greg Canavan, P-DO• Randy Spaulding, ISU• Lori Waters, D-5• Jay Elson, D-5

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Delayed neutron measurement Materials spanning the periodic

chart - 12C to 238U Simple targets

• 10s or 100s of gram samples

Simple counters• 3He gas mixture proportional counter• LaBr

Vacuum Beam Pipe

He3 detector andLaBr detector

34-in target distance

Target ladder for small “bare”targets

Slide 4

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Proton interrogation of materials pRad facility is well suited.

• Pulse on demand• Current monitor• Beam profile from cameras

Beta-delayed emissions diagnostic for uranium

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0 10 20 30 40 50 60 70 80 90 100Time (sec)

Cross section (mb/sec)

238U

235U

Lead

Tungsten

Iron

Copper

Aluminum

18O

Carbon

16O

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Time (sec)

Cross section (mb/sec)

238U

235U

Lead

Tungsten

Iron

Copper

Aluminum

18O

Carbon

16O

Slide 5

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Delayed neutron cross sections vs. A Delayed neutrons from Pb, Hg, Au

appear to arise from fission. 18O has the highest delayed neutron

production of all targets measured. Typical background materials like

iron and Aluminum have cross sections ~1/100th of Uranium

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Atomic Mass

Cross section (mb)

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Compound targets Preliminary investigation of

shielding effects• ‘Environmental’ clutter• Intentional shielding

DU: 1”x4”x4”

Pb: 2”x4”x8”

Null

Quad He3 detector315-cm target distance

310

He3 detector andLaBr detector

173-cm target distance440

Proton Beam centerline

22.50

ShieldingWater, Al, Steel, PbVarious thicknesses

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Relative neutron yields from compound targets

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Present Proposal Detector development

• Multi-layered array• Neutron energy binning

Gamma signal Additional targets

• Simple, A = 100-150• Compound

~4’ x 4’ detectorlocations

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Detector Development 3He mixture proportional tubes CH2 moderator Layered for energy binning

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Targeting A = 100 - 150

• Pd, Ag, Sn, I, Cs, La, Sm, Gd

Compound Targets• Materials in front of targets• Materials around targets• Materials behind targets

Slide 11

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Time Request 30 - 50 targets and scenarios Average of ~1 target per hour, including setup & overhead Repeat some measurements at multiple detector distances Time is ~ 60 hours ‘Cycle B’ Fridays work