TRIUMF licensed Standard 18F- Water Target

The standard water target is a TRIUMF licensed 18F- water target for proton irradiation. The picture below shows a solid model of the target. The target consists of a niobium water cooled body and aluminum helium cooled window and nose flange. The target is electrically isolated from the beamline through a hard coat anodizing. Helium and water cooling connect to the target with Swagelok fittings. Use of a simple radial o-ring seal on the nose flange makes for easy removal from hot beamlines for servicing. Oxygen enriched water is loaded and unloaded through Ø1/16” Upchurch fittings located on the back of the target.


Fig. 1: Standard Water Target

Feature

  • Water cooled niobium target body
  • Helium cooled window
  • Hard coat anodized aluminum nose flange
  • Reliable all metal Swagelok fittings
  • Ø10.0 mm Target window with Niobium coated Havar foil
  • Ø12mm x 8 mm Target cavity
  • 88 x 89 x 78mm Target volume envelope

 


Fig. 2: Standard Water Target

Application

The standard water target is a useful upgrade for medium energy proton accelerators. The niobium target can increase yield and decrease activation over stainless steel or silver targets. Paired with the helium cooling cabinet and target support cabinet two standard water targets can be implemented with little support. Because of its small envelope size it can replace larger single target systems with a dual target system reducing down time.

Technical Performance Characteristics

The standard water target is designed to operate at 30µA at 14 MeV. The target has been successfully operated up to 40µA @ 14MeV. The maximum power handling of the standard water target has not been tested. The physical and performance characteristics of the standard water target are as follows:

  • Energy loss through window: 0.8MeV
  • Operating pressure: up to 500 psi
  • Power handling: 30 to 40µA @14MeV
  • Energy 14Mev

The table below lists estimated theoretical and practical yield. Each case assumes the use of highly enriched target material (>95%), no correction is made for enrichment. Theoretical production yields are reported from IAEA-TECDOC-1211 published May 2001. All targets are considered "thick" to the beam, meaning the proton beam is stopped in the target material. Practical yields are what are anticipated to be recovered from the target. Yields are given for a 2 hour irradiation at end-of-bombardment for irradiation at maximum current. Incident energy is corrected for the energy loss to transit the entrance foil(e.g. 15 MeV results in ~14.2 MeV incident on the 18O). Practical yields are based on a 50% recovery from the water target. These are values achieved in systems at TRIUMF.


Interface Technical Specifications

Helium cooling, loading, unloading, pressure reading and beam current readback can be handled by the target support Cabinet and helium cooling cabinets.

Connection to Beamline
  • Ø40.0 mm x 10.5mm nose flange with radial o ring port

Cooling

  • Helium Cooling
    • 60 LPM at Standard temperature and pressure
    • Ø8mm non conducting tube (Polyurethane)
  • Water Cooling
    • Deionized water
    • Ø8mm non conducting tube (Polyurethane)
  • O18/ F18 water transfer:
    • Ø1/16” tubing (PEEK)
Beam current readback
  • M3 connector to 18awg wire.