The Casimir Effect from a Condensed Matter Perspective

The Casimir effect, a key observable realization of vacuum fluctuations, is usually taught in graduate courses on quantum field theory. The growing importance of Casimir forces in microelectromechanical systems motivates this subject as a topic for graduate many-body physics courses. To this end, we revisit the Casimir effect using methods common in condensed matter physics. We recover previously derived results and explore the implications of the analogies implicit in this treatment.Comment: Accepted for Publication in American Journal of Physic

AtmoCube: observation of the near Earth space environment to study "space weather" effects

AtmoCube represents an innovative measurement system for the study of the near Earth space environment starting from about 400 km altitude. It appears as a cubic nano-satellite, 13 cm side, with a total mass of 1.3 kg (aluminum structure). The scientific instrument is a spectral dosimeter monitoring the radiation environment. The payload also includes a magnetometer and a GPS. The goal is to build a precise map of the Earth magnetic field and of the flux of radiation impinging on the instrument, which is related to Space Weather effects. The GPS, providing the position of the region where the measurements are performed and the corresponding time instant, allows to correlate these measurements with other measurements performed on Earth and from the Space and therefore with the indexes of the Solar activity. In addition the GPS allows an indirect measurement of the atmospheric density. -------------------------------------------------------------------------------

Relativistic electron fluxes and dose rate variations observed on the international space station

The paper presents observations of relativistic electron precipitations (REP) on the International Space Station (ISS) obtained by three Bulgarian-built instruments flown in 2001 and 2008–2010. The first data are from the Liulin-E094 instrument flown in May–August 2001 inside the US laboratory module of the ISS. Next the time profiles of the REP-generated daily fluences and the absorbed doses at the orbit of ISS during the period February 2008–August 2010 are analyzed in dependence of the daily Ap index and compared with the daily relativistic electron fluence with energies of more than 2 MeV measured by the GOES. The REP in April 2010 being the second largest in GOES history (with a >2 MeV electron fluence event) is specially studied

The Solar Particle Event on 10 September 2017 as observed on-board the International Space Station (ISS)

The nominal radiation environment in Low Earth Orbit (LEO), especially for the International Space Station (ISS), is dominated by two sources. The first is galactic cosmic radiation (GCR) which is modulated by the interplanetary and the Earth‟s magnetic fields and the second is trapped radiation in the form of the Van Allen Belts. The trapped radiation inside the ISS is mostly due to protons of the inner radiation belt. In addition to these sources sporadic Solar Particle Events (SPEs) can produce high doses inside and outside the ISS, depending on the intensity and energy spectrum of the event. Before 2017, the last SPE observed inside the ISS with relevant radiation detectors occurred in May 2012. Even though we are currently approaching the next solar minimum, an SPE was observed in September 2017, which was a) a Ground Level Enhancement (GLE 72); b) measured with various radiation detector systems on-board the ISS and c) observed on the surface of Mars. This paper gives an overview of the 10 September 2017 SPE measured with the DOSIS 3D-DOSTEL and the ISS-RAD (Radiation Assessment Detector) instruments, both located at this time in close proximity to each other in the Columbus Laboratory of the ISS. The additional dose received during the SPE, was 146.2 µGy in Si as measured by ISS-RAD and 67.8 µGy in Si as measured by the DOSIS 3D-DOSTEL instruments. In comparison, the dose measured on the surface of Mars with the MSL-RAD (Mars Science Laboratory) instrument accounted to 418 µGy in Si