Changes between Version 62 and Version 63 of AstroTechTalk

Timestamp:

5 Feb 2015, 16:13:30 (9 years ago)

Author:

Ralph Hofferbert

Comment:

--

AstroTechTalk

@@ -30 +30 @@
 || '''30.01.2015''' || '''Peter Hartmann (Schott AG)''' ||'''ZERODUR®: Glass ceramic with ultra-low thermal expansion '''[[BR]][[BR]]Requirements on shape and dimensional stability of high tech components are continuously growing. Mirror shape profile must be kept constant within 10 nm, in microlithography silicon wafers must be positioned to 0.3 nm precision. Active temperature stabilization must be complemented by using materials which change their extension lowest possible with temperature variations.[[BR]][[BR]]Here the glass ceramic ZERODUR® takes a prominent position with more than 45 years of successful application. Even though being unchanged in its composition it was subject of significant progress nonetheless in the last ten years. The production process enables mirrors of 4 and 8 m size with extreme homogeneity of the coefficient of thermal expansion in the 10^-9^/K range. Tempering processes basing on a physical model allow keeping CTE within limit of +/- 7×10^-9^/K. Even matching relative expansion Delta l/l to given temperature profiles for example for observatories is possible down to 10×10^-9^. CTE minimization is also possible for the temperature range 70 to 250 K. Bubbles, inclusions and striae content is very low as well as residual bulk stress. New processing methods enable lightweight structures with almost 90% weight reduction. Better modelling and an increased data base for bending strength support application at higher mechanical loads.[[BR]][[BR]]A large number of earth-bound and space-based projects prove the high material quality and its reproducibility, which is a decisive precondition for extremely large telescopes.[[BR]][[BR]]Talk: German[[BR]][https://svn.mpia.de/trac/gulli/att/raw-attachment/wiki/WikiStart/2015-01-30_Zerodur.pdf Slides: English][[BR]]Questions: German, English ||
 || '''06.02.2015[[BR]][[span(style=color: #FF0000, (11:15hrs))]]''' || '''Matthias Lezius[[BR]](Menlo Systems)''' || '''Technology and applications of frequency comb lasers'''[[BR]][[BR]]The optical frequency comb is the core product of Menlo Systems GmbH. Since its invention it has triggered numerous applications in very demanding areas of science like e.g. ultra high resolution spectroscopy, calibration of (astronomical) spectrometers, precision ranging, optical clocks, ultra-pure micro-wave generation, frequency and time transfer. In a general sense it has become the swiss knife of precision metrology of time, frequency, and length. Even mass and gravitation have been reported to be measurable at increased precision using the frequency comb. [[BR]][[BR]]In the present talk Matthias Lezius will present todays technologies how to build optical frequency combs based on femtosecond lasers, and how to apply this device to various metrological challenges. [[BR]][[BR]]Talk: German[[BR]]Slides: English[[BR]]Questions: German, English ||
-|| 13.02.2015 || Martin Kuerster || Allocation of the MPIA integration halls in 2015 ||
+|| '''13.02.2015''' || '''Martin Kuerster''' || '''Allocation of the MPIA integration halls in 2015'''[[BR]][[BR]]A lot of important maneuvers are planned in the three large integration halls at MPIA in 2015. Therefore, we use this week's talk for some programmatic discussions about needs and assumptions. Martin Kuerster will present the basic planning constraints to allow for a (preliminary) mutual agreement and fixation between all involved parties.   [[BR]][[BR]]The following activities are scheduled in the "Montagehalle",[[BR]]the "Experimentierhalle" and the "Reinraumschleuse":[[BR]] * AIV, packing and transport for CARMENES incl. its test equipment [[BR]] * Analogical for LINC-NIRVANA [[BR]] * Remaining tasks for and storage of GRAVITY and MATISSE [[BR]] * Open House Day installations and layout [[BR]] * Implications for the outdoor area in front of the "Reinraumschleuse" [[BR]] * Future use of the halls [[BR]] [[BR]]Everybody is cordially invited. Attendance of the mentioned teams incl. project leaders/managers is vital for the discussion. Furthermore, persons with a perspective or a clear plan for an allocation of the hall(s) would be very helpful.[[BR]][[BR]]Talk: German[[BR]]Slides: English[[BR]]Questions: German, English ||
 || '''20.02.2015''' || '''Ralf-Rainer Rohloff''' || '''Carbon fiber components in astronomical instruments'''[[BR]][[BR]]Nowadays carbon fiber reinforced plastic (CFRP) is a standard material in aerospace applications. But also in other industrial fields, where products are driven by a low mass in conjunction with a high stiffness, like e.g. in vehicle construction or even sports equipment development, CFRP becomes more and more important.[[BR]][[BR]]There is an increasing trend to apply carbon fiber parts also in astronomical instrumentation. One of the pioneers in this field is the interferometric camera LINC-NIRVANA for the Large Binocular Telescope (LBT). The talk will also discuss other examples in other projects. In addition the properties and the manufacturing process of this interesting material will be described.[[BR]][[BR]]Talk: German[[BR]]Slides: English[[BR]]Questions: German, English ||
 || 27.02.2015 || Sascha Douffet || Occupational safety at MPIA ||