Lifetime and strength tests of tantalum and tungsten under thermal shock for a Neutrino Factory target

Generic study on the design and operation of high power targets

“…Compared to tungsten, tantalum seems to have a lower resistance to thermal stresses because of its low yield strength at high temperatures. This is in agreement with previous comparative studies of tungsten and tantalum targets reported in [6,7]. Beryllium was found to have the highest rate of thermal resistance decrease over the temperature range, where data was available.…”

“…The formation and effects of thermal stresses in high power targets have been studied extensively over the past few years [5][6][7][8]. With many target materials proposed, it is essential to be able to draw quick comparisons of the different merits of these materials, in order to facilitate the engineering design and material selection process.…”

Experimental results and constitutive modelling for tungsten and tantalum at high strain rates and very high temperatures

“…The method is based on heating and stressing a thin wire (less than 1 mm diameter) of the candidate material by a fast (∼ 1µs long), high current (up to 9200 A) pulse. This paper is a continuation of the study presented in [5] where the yield strength of tungsten and tantalum has been measured at strain rates from 500 to 1500 s −1 and at temperatures much higher than previously recorded in the literature. The highest temperature reached in the experiment was 2250 0 C and 2450 0 C, for tantalum and tungsten, respectively.…”

“…As part of the UK programme of high power target developments for a Neutrino Factory [3] a new dynamic method for thermomechanical characterization of the candidate materials (tungsten and tantalum in this case) has been developed [4,5]. The method is based on heating and stressing a thin wire (less than 1 mm diameter) of the candidate material by a fast (∼ 1µs long), high current (up to 9200 A) pulse.…”

Particle production and energy deposition studies for the neutrino factory target station

“…In contrast, the solid tungsten target itself experiences a much larger energy deposition, corresponding to a quarter of the total beam power. Experimental work using fast, high current pulses passing through tungsten wires has demonstrated that a 20 cm-long, 2 cm diameter tungsten target will be able to withstand the peak stresses from such an energy deposition, allowing a target lifetime of at least three years [17]. The removal of the reservoir pool for the solid target means that about 5% more energy is deposited in the shielding, with a slight reduction in the radiation dose absorbed by the downstream beam pipe.…”