ALMA Observations of the Sun in Cycle 4 and Beyond

This document was created by the Solar Simulations for the Atacama Large Millimeter Observatory Network (SSALMON) in preparation of the first regular observations of the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA), which are anticipated to start in ALMA Cycle 4 in October 2016. The science cases presented here demonstrate that a large number of scientifically highly interesting observations could be made already with the still limited solar observing modes foreseen for Cycle 4 and that ALMA has the potential to make important contributions to answering long-standing scientific questions in solar physics. With the proposal deadline for ALMA Cycle 4 in April 2016 and the Commissioning and Science Verification campaign in December 2015 in sight, several of the SSALMON Expert Teams composed strategic documents in which they outlined potential solar observations that could be feasible given the anticipated technical capabilities in Cycle 4. These documents have been combined and supplemented with an analysis, resulting in recommendations for solar observing with ALMA in Cycle 4. In addition, the detailed science cases also demonstrate the scientific priorities of the solar physics community and which capabilities are wanted for the next observing cycles. The work on this White Paper effort was coordinated in close cooperation with the two international solar ALMA development studies led by T. Bastian (NRAO, USA) and R. Brajsa, (ESO). This document will be further updated until the beginning of Cycle 4 in October 2016. In particular, we plan to adjust the technical capabilities of the solar observing modes once finally decided and to further demonstrate the feasibility and scientific potential of the included science cases by means of numerical simulations of the solar atmosphere and corresponding simulated ALMA observations.Comment: SSALMON White Paper with focus on potential solar science with ALMA in Cycle 4; 54 pages. Version 1.2, March 29th, 2016 (updated technical capabilities and observing plans

Melt homogenization and self-organization of chalcogenides glasses: evidence of sharp rigidity, stress and nanoscale phase separation transitions in the GexSe100-x binary

A Raman profiling method is used to monitor growth of GexSe100-x melts and reveals a two step process of homogenization. Resulting homogeneous glasses show the non-reversing enthalpy at Tg, {\Delta}Hnr(x), to show a square-well like variation with x, with a rigidity transition near xc(1) = 19.5(5)% and stress transition near xc(2) = 26.0(5)%) representing the boundaries of the rigid but stress-free Intermediate Phase (IP). The square-well like variation of {\Delta}Hnr(x) develops sloping walls, a triangular shape and eventually disappears in glasses having an increasing heterogeneity. The {\Delta}Hnr term ages over weeks outside the IP but not inside the IP. An optical analogue of the reversibility window is observed with Raman spectra of as-quenched melts and Tg cycled glasses being the same for glass compositions in the IP but different for compositions outside the IP. Variations of Molar volumes, display three regimes of behavior with a global minimum in the IP and a pronounced increase outside that phase. The intrinsic physical behavior of dry and homogeneous chalcogenides glasses can vary sharply with composition near elastic and chemical phase transitions, showing that the physics of network glasses requires homogeneous samples, and may be far more interesting than hitherto recognized

Robotic Follow-Up for Human Exploration

We are studying how "robotic follow-up" can improve future planetary exploration. Robotic follow-up, which we define as augmenting human field work with subsequent robot activity, is a field exploration technique designed to increase human productivity and science return. To better understand the benefits, requirements, limitations and risks associated with this technique, we are conducting analog field tests with human and robot teams at the Haughton Crater impact structure on Devon Island, Canada. In this paper, we discuss the motivation for robotic follow-up, describe the scientific context and system design for our work, and present results and lessons learned from field testing

The Good, the Bad, and the Actively Verified

We believe that we can use active probing for compromise recovery. Our intent is to exploit the differences in behavior between compromised and uncompromised systems and use that information to identify those which are not behaving as expected. Those differences may indicate a deviation in either con figuration or implementation from what we expect on the network, either of which suggests that the misbehaving entity might not be trustworthy. In this work, we propose and build a case for a method for using altered behavior directly resulting from or introduced as a side-effect of the compromise of a network service to detect the presence of such a compromise. We use several case studies to illustrate our technique, and demonstrate its feasibility with a software tool developed using our method

Unraveling surface enabled phenomena in low-dimensional molecular systems

This thesis focuses on the investigation of on-surface molecular architectures which exhibit extraordinary magnetic and quantum properties originating from the reduced dimensionality at surfaces. Many different combinations of spin-bearing square planar molecules and substrates were used and probed by local techniques as well as by spatial averaging techniques. Probing low-dimensional molecular magnetism by combination of several complementary techniques provides a more complete insight into the subtle interplay of the interactions involved at the surfaces. The comprehensive study of magnetism of Cr-phthalocyanine molecules supported on several different ferromagnetic and non-magnetic substrates demonstrated how the spin state of such molecules depends on the interaction with the substrate. Also in my work I have shown that the relative orientation of the molecule’s and the substrate’s easy magnetization axes is of great importance, even for molecules which are paramagnetic in the bulk. This is further supported by the example of interactions of Cr-based adsorbates with the Au(111) substrate where, for example, a very strong anisotropy of the Cr magnetic moment is observed. At the same time, the exchange coupling interactions with bare ferromagnetic substrates, Co and Ni are different in both the intensity and sign. These observations indicate that a refinement of the current models describing interface magnetism is needed to understand the peculiar magnetic coupling in these systems. Study of various phthalocyanine molecules on Pb(111) demonstrate the importance of employment of X-ray based techniques to complement the local probe investigations of these spin systems coupled to a superconductor. Although such experiments can drive a system out of the superconductive phase by the presence of a magnetic field, it was shown that some magnetic properties of these molecules won’t depend greatly on whether the system is or is not in the superconducting state. This fact is making X-ray based investigations even more important. The emergence of interesting magnetic phenomena through intra- and inter-molecular interactions was addressed next. Pilot experiments performed on triply-fused bisporphyrin molecules opened up the field for a new class of molecules containing two spin centers that can be exchanged providing a plethora of possibilities for tuning the molecule’s magnetic properties. Following up on our recent observation of long range 2D ferrimagnetic ordering in heteromolecular checkerboard assemblies of Fe and Mn phthalocyanine molecules supported on Au(111), we performed the experiments with similar binary 2D systems to further glimpse into the role of 3d orbitals, their symmetries and filling in maintaining long range ordering. It was shown that depending on the configuration and filling of their 3d orbitals the metallo-phthalocyanine molecules will interact by the RKKY interaction or not. In addition, I reported on a significant asymmetry in the mixing of hetero molecular layers that is occurring due to the pinning of one of the molecular types to the surface. Surprisingly this process modifies the layer structure of multilayers and therefore needs to be taken into account for on-surface metalation reactions or for the design of spintronic devices. Further on, different ways of modification of magnetic properties have been investigated. We reported on how spin states of various phthalocyanine molecules can be altered upon exposure to molecular and atomic hydrogen. In the former case, this process is completely reversible, while in the latter case it leads to irreversible changes of both the spin state of the metal center and of the molecule. Also, the ability to induce a Co surface functionalization with both N and Cl adlayers is demonstrated. Here, X-ray Photoelectron Diffraction has been employed to precisely determine interatomic distances in the created functionalized surfaces. In the last part the importance of development of new preparation/characterization techniques is demonstrated. It is shown how we successfully implemented the technique of deposition of large non-sublimable molecules into the UHV directly from solution, and how we have adapted a detector that is commonly used in time-of-flight mass spectrometry for acquiring fast, time-resolved XAS signal at SIM beamline of the SLS. In short, this thesis represents a collection of several pieces of a larger scientific puzzle grazing through several aspects of molecular magnetism

Using embedded sensors for detecting network attacks

Embedded sensors for intrusion detection consist of code added to the operating system and the programs of the hosts where monitoring will take place. The sensors check for specific conditions that indicate an attack is taking place, or an intrusion has occurred. Embedded sensors have advantages over other data collection techniques (usually implemented as separate processes) in terms of reduced host impact, resistance to attack, efficiency and effectiveness of detection. We describe the use of embedded sensors in general, and their application to the detection of specific network-based attacks. The sensors were implemented in the OpenBSD operating system, and our tests show a 100 % success rate in the detection of the attacks for which sensors were instrumented. We discuss the sensors implemented and the results obtained, as well as current and future work in the area