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Positronium for Antihydrogen Production in the AEGIS Experiment

100%

Consolati G., Aghion S., Amsler C., Bonomi G., Brusa R., Caccia M., Caravita R., Castelli F., Cerchiari G., Comparat D., Demetrio A., Di Noto L., Doser M., Evans C., Fanì M., Ferragut R., Fesel J., Fontana A., Gerber S., Giammarchi M., Gligorova A., Guatieri F., Haider S., Hinterberger A., Holmestad H., Kellerbauer A., Khalidova O., Krasnicky D., Lagomarsino V., Lansonneur P., Lebrun P., Malbrunot C., Mariazzi S., Marton J., Matveev V., Mazzotta Z., Müller S., Nebbia G., Nedelec P., Oberthaler M., Pacifico N., Pagano D., Penasa L., Petracek V., Prelz F., Prevedelli M., Ravelli L., Rienaecker B., Robert J., Røhne O., Rotondi A., Sandaker H., Santoro R., Smestad L., Sorrentino F., Testera G., Tietje I., Widmann E., Yzombard P., Zimmer C., Zmeskal J., Zurlo N.

Acta Physica Polonica A

2017

vol. 132

issue 5

1443-1449

The primary goal of the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEGIS) collaboration is to measure for the first time precisely the gravitational acceleration of antihydrogen, H̅, a fundamental issue of contemporary physics, using a beam of antiatoms. Indeed, although indirect arguments have been raised against a different acceleration of antimatter with respect to matter, nevertheless some attempts to formulate quantum theories of gravity, or to unify gravity with the other forces, consider the possibility of a non-identical gravitational interaction between matter and antimatter. We plan to generate H̅ through a charge-exchange reaction between excited Ps and antiprotons coming from the Antiproton Decelerator facility at CERN. It offers the advantage to produce sufficiently cold antihydrogen to make feasible a measurement of gravitational acceleration with reasonable uncertainty (of the order of a few percent). Since the cross-section of the above reaction increases with n⁴, n being the principal quantum number of Ps, it is essential to generate Ps in a highly excited (Rydberg) state. This will occur by means of two laser excitations of Ps emitted from a nanoporous silica target: a first UV laser (at 205 nm) will bring Ps from the ground to the n=3 state; a second laser pulse (tunable in the range 1650-1700 nm) will further excite Ps to the Rydberg state.

Analysis of a Skid Type Landing Gear of a Rotary Wing UAV by Experimental and Numerical Methods

75%

Yildirim O., Günay E., Anil Ö., Aygün C.

Acta Physica Polonica A

2015

vol. 127

issue 4

1170-1175

The objective of this study was to analyze the results obtained from tests done by simulating the crash landing of a rotary wing unmanned air vehicle with a skid type landing gear. The experimental and computational methods were used in the simulation tests. In the first portion of the test; namely with the experimental method, the impact loads induced by the simulated crash landing and the stresses, strains, deformations generated by these loads, were recorded by drop test apparatus. In the second portion of the test with the computational method, free falling of the skid type landing gear was modeled and crash landing test was simulated numerically by using ANSYS code. Experimental methods were applied on four skid landing gear specimens with different shapes. Each of the test samples used in the following test was evolved because each sample was developed and redesigned based on the feedback results obtained from the former test.The first three test specimens were manufactured from 2024 T3, 7075 T6 and 6061 T6 aluminum alloys respectively and all of them were curved in Π-form with a solid cross section. The last and fourth specimen was also manufactured from 6061 T6 aluminum alloy and it was curved in a hollow semi-circle form (∩-form). It is concluded that the last and fourth developed specimen was the best in absorbing the impact energy and enduring the crash.

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Positronium for Antihydrogen Production in the AEGIS Experiment

Analysis of a Skid Type Landing Gear of a Rotary Wing UAV by Experimental and Numerical Methods