IODINE-125

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Proc. Japan Conf. Radioisotopes

OSTI ID:4691987

Harper, P V; Siemens, W D; Lathrop, K A; Brizel, H E; Harrison, R W

There may be some advantage in substituting iodine-125 for iodine-131 in a number of clinical and experimental situations. Among these advantages are: the long half life of iodine-125 (60 days), which results in a greatly increased shelf-life of tagged compounds; the low energy (27 kev) of its photon radiations, which reduces shielding requirements and permits more efficient detector design; and the low energy dissipation rate, which reduces radiation damage to tagged compounds. These factors allow enhanced counting efficiency and scanning resolution and lead to decreased radiation dosage and increased tolerable isotope dosage. The availability of the isotope, however, is greatly limited because production in the cyclotron from tellurium, even when enriched target material is used, results in heavy contamination with the undesirable 13-day iodine126, making the resultant product unsuitable for human and experimental use to a considerable extent. The production is described of iodine-125, as a daughter product from the neutron activation of xenon-124 to xenon-125 This method makes available curie quantities of material wfth greater than 98% purity at a cost of approximately five dollars a millicurie. The thermal neutron activation cross section of xenon-124 is found to be 115 barns with a resonance activation integral of 1210 barns. While this permits production of large amounts of iodine- 125, unfontunately the product iostope itself has a high thermal neutron activation cross section of 890 barns and a resonance activation integral of 6500 barns, so that iodine-126 formation from iodine-125 must be limited by shortening the activation time or lowering the neutron flux. (T.F.H.)

• Research Organization: Argonne Cancer Research Hospital
• NSA Number: NSA-17-030012
• OSTI ID: 4691987
• Journal Information: Proc. Japan Conf. Radioisotopes, Journal Name: Proc. Japan Conf. Radioisotopes Vol. Vol: 4th
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACTIVATION
CONTAMINATION
CROSS SECTIONS
CYCLOTRONS
ECONOMICS
EFFICIENCY
ENERGY
ENRICHMENT
GENERAL AND MISCELLANEOUS
HALF-LIFE
IODINE 125
IODINE 126
IODINE 131
LOSSES
MEDICINE
NEUTRONS
PLANNING
PRODUCTION
RADIATION DETECTORS
RADIATION DOSES
RADIATION INJURIES
RADIATIONS
RESOLUTION
RESONANCE ESCAPE PROBABILITY
SAMPLING
SHIELDING
TARGETS
TELLURIUM
XENON 124
XENON 125