# Presentation: 042325

## Nuclear Technique in Forensic Science

- Ta-Chung Ong
- NCSS

## What is Nuclear Forensic?

- Extract information from evidence
- Radioactive material
- What? Where? When?
- Isotopic composition
- Place of origin
- Age
- Track the material, solve the crime

## Applications

- Homeland Security
- Nuclear Weapon
- Dirty Bomb
- Drug Law Enforcement
- Thorium and methamphetamine
- Elemental Analysis
- “Red Mercury” hoax

## Homeland Security

- Danger of nuclear proliferation after Cold War
- Soviet nuclear material (U and Pu)
- Lack proper security
- Close proximity to unfriendly nations (i.e. Iran) and terrorist organizations (i.e. Al-Qaeda)
- Some material seized in Germany and Czech Republic

## Homeland Security

- Seized material as evidence
- Origin determination
- Isotopic composition (fingerprint)
- Pinpoint place of production
- Age determination
- Parent/daughter ratio
- Determine time of last purification

## Homeland Security

- Isotopic Composition
- Measure ratio of 234U, 235U, 236U, 238U, 239Pu, 240Pu, and 242Pu
- Mass Spectrometry
- Match result to database of known material
- Pinpoint place of production

## Homeland Security

- Age Determination
- Parent/Daughter Ratio: 234U/230Th and 235U/231Pa
- Th and Pa are in small concentration
- Need accurate and precise separation
- Solvent Extraction Chromatography
- Alpha and Gamma Spectroscopy

## Drug Law Enforcement

- ThO2
- Catalyst in the synthesis of phenylacetone (P2P) from acetic and phenylacetic acid
- P2P is an intermediate in the synthesis of methamphetamine
- Determine source and age of ThO2 seized in clandestine lab

## Drug Law Enforcement

- Determine source of purified ThO2
- No detectable U
- 232Th/230Th pair (not parent/daughter!)
- Calculate 238U
- Reveal composition of 232Th and 238U
- Match result to ore database, determine ore body

## Drug Law Enforcement

- Determine age of ThO2
- 232Th/228Th pair (parent/daughter)
- 232Th, 228Ra, 228Th equilibrium (ore)
- No 228Ra in purified ThO2
- Smaller amount of 228Th in purified sample than ore

## Elemental Analysis

- Elemental Composition of metal
- X-ray fluorescence
- Gamma and alpha spectroscopy

## Elemental Analysis

- Example: Red Mercury hoax
- Mythical ballotechnic substance (emit energetic gamma ray)
- Can trigger fusion
- Make portable H-bomb possible
- Never have been found

## Elemental Analysis

- Perpetration of the hoax
- Existence strongly advocated by Sam Cohen, inventor of neutron bomb
- Black Market and would-be terrorists
- Price of Red Mercury: $500,000/Kg
- Advertised as ballotechnic, or highly enriched uranium, or component to missile guidance system

## Elemental Analysis

- Analysis of seized “Red Mercury” in Livermore National Lab
- Brownish red liquid
- X-ray fluorescence: Mostly Hg, some Cd, Ag, and Zn
- Gamma Spectroscopy: Indistinguishable from background
- Conclusion: Ordinary mercury!

## Elemental Analysis

- Possible candidate for Red Mercury
- Cinnabar (HgS)
- HgI2 (Red Color)
- Any other mercury or mercury oxide with red pigment
- Codename for something else, not mercury at all
- Search continues...

## Conclusion

- Nuclear Forensic
- Extract Information from seized evidence
- Isotopic Composition
- Place of origin/production
- Age
- Provide valuable aid in criminal investigation