Speaker
Description
The ISIS Synchrotron operates two Target Stations (TS). TS1 is the oldest and has been operating for nearly 40 years. TS2 came onstream in 2009 adding an additional suite of instruments for scientific research.
Both Target Stations have solid Tungsten Targets clad in Tantalum, which are water-cooled. TS1 Target receives beam power of 160µA at 800 MeV and has proved to be very reliable with a service life of around 5 years. Even though TS2 Target receives only a quarter beam power (40µA) it has a shorter service life of around 2 years. A gamma spectroscopic analysis (gamma spec) is taken during regular maintenance periods to look for evidence of W187 leaching into the cooling water. This is the trigger for changing the Target.
The failure mode is believed to be a breach in the tantalum cladding allowing cooling water to contact the tungsten core. There are several mechanisms that could cause or contribute to this failure.
Post Irradiation Examination (PIE) of a used TS2 Target will provide valuable information regarding the primary mechanism for failure and will focus attention on how to mitigate the problem and extend the service life of the target towards the design goal of 5 years.
Planning for the PIE operation is at an advanced stage with the bespoke tooling having been designed, built, and tested. Full mock tests in the offline Remote Handling Facility have been carried out in preparation for the operation to take place in January 2024.
This presentation will describe in detail the design of the bespoke tooling and the experience gained through offline Remote Handling trials in cutting the end from a mock (tantalum) target to expose the inner surfaces for visual inspection and evaluation.
The severed end cap will be packaged separately from the remainder of the target with the intention of carrying out materials analysis at some point in the future to increase our knowledge of tantalum’s material properties in a highly irradiated state.
| Themes for the contribution | 3 Post-irradiation examination: |
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