3 research outputs found
Drop impact onto a cantilever beam:behavior of the lamella and force measurement
No full textIn this work, the process of drop impact onto an elastic surface (a cantilever beam) was studied. Different from previous studies which typically focused on the behavior of the elastic surface (e.g., deformation and oscillation), the focus of this work is to examine the behavior of the resulting lamella during the impact. It was found that the maximum contact diameter of the lamella in an elastic impact compared to impact onto a ridged surface is significantly smaller (e.g., 17% for impact at 2 m/s). The results were explained through an analysis of impact energy and the stored elastic energy in the beam. In this work, we also demonstrated how to use a cantilever beam to measure maximum drop impact force. It was found that a large natural frequency of the cantilever beam is needed for the maximum force measurement to produce acceptable values.</p
Successful cooling of a pixel tracker using gaseous helium: studies with a mock-up and a detector prototype
No full textWe report the successful operation of a functional pixel detector with
gaseous helium cooling. Using an accurate mock-up beforehand, the cooling was
validated. We use a miniature turbo compressor to propel the helium at
under ambient pressure conditions with gas temperatures above . Our
earlier results based on computational fluid dynamics simulations and a much
simpler mock-up are confirmed. With this, we paved the path to cool pixel
detectors in experimental particle physics at heat densities up to using helium. This enables cooling of detectors with very low mass
requirements, minimising the effects of multiple Coulomb scattering
effectively. The concept presented here is not limited to pixel detector
applications and can be used to cool any surface with comparable
heat-densities, only limited by shaping the helium gas flow
