29th Symposium on Fusion Technology (SOFT 2016)

P3.003 Accelerometers for boiling onset detection on beam stopper of LIPAc accelerator

Sep 7, 2016, 11:00 AM

1h 20m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 3

Poster A. Experimental Fusion Devices and Supporting Facilities P3 Poster session

Speaker

Fernando Arranz (Laboratorio Nacional de Fusion)

Description

The LIPAc (Linear IFMIF Prototype Accelerator) is a prototype that ends in a Dump made of copper with conical shape and cooled by water moving at high speed on the outer surface. The shape of the dump is intended for a redistribution of a very high density power of the deuteron beam to be stopped (1.12 MW) leading during normal operation to reasonable temperatures and thermal stresses well below the safety margins. In case the beam reaches the dump with abnormal misalignment or offset, the local temperatures at the water-copper surface will give rise to boiling onset which can be used as a warning flag before an excessive thermal stress distribution could endanger the mechanical integrity of the Beam Dump. Previous experiments having the same goal were carried out with hydrophones to detect the onset of boiling [doi:10.1016/j.fusengdes.2015.01.011]. The current article deals with the treatment of the signal coming from an accelerometer. The article will go into detail of the advantages and drawbacks of the accelerometer versus the hydrophone as the sensor to be used. Improvements in the data treatment to refine the detection of the boiling onset will be explained as well. Real case problems like the noise coming from external or undesired sources are considered and a number of recommendations are derived for the implementation of the system in the cooling system of the LIPAc Beam Dump to be installed in Rokasho. This work has been partially funded by the MINECO Ministry under project FIS2013-40860-R and the agreement as published in the Spanish BOE (BOE n14, p. 1988).