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The design, manufacture and characterization of lightweight carbon-fiber spherical converging mirrors for the RICH 1 Cherenkov detector of the LHCb experiment at CERN are described. The mirrors need to be lightweight to minimize the material for traversing particles and fluorocarbon-compatible to avoid degradation in the C4F10 gas radiator of RICH 1. Four large-sized carbon-fiber mirrors covering a total surface area of ∼ 2 m 2 were installed in RICH 1 in July 2007. The mirrors have a radius of curvature of ∼ 2700 mm , a high reflectivity of ∼ 90 % in the 200–600 nm wavelength band, a low areal density of ∼ 5 kg / m 2 equivalent to ∼ 1.2 % of a radiation length. Results of the radiation and fluorocarbon testing of the mirror prototypes are also reported.

AMiBA is the largest hexapod astronomical telescope in current operation. We present a description of this novel hexapod mount with its main mechanical components -- the support cone, universal joints, jack screws, and platform -- and outline the control system with the pointing model and the operating modes that are supported. The AMiBA hexapod mount performance is verified based on optical pointing tests and platform photogrammetry measurements. The photogrammetry results show that the deformations in the inner part of the platform are less than 120 micron rms. This is negligible for optical pointing corrections, radio alignment and radio phase errors for the currently operational 7-element compact configuration. The optical pointing error in azimuth and elevation is successively reduced by a series of corrections to about 0.4 arcmin rms which meets our goal for the 7-element target specifications., Comment: Accepted for ApJ, 33 pages, 15 figures

The Array for Microwave Background Anisotropy is a 7-element interferometer sited on Mauna Loa, Hawaii. The seven 60cm telescopes are mounted on a 6-meter platform, and operates at 3mm wavelength. In October 2006, the telescope was officially dedicated and renamed as the Y. T. Lee AMiBA. During 2007, scientific operations have begun, after a long process of calibration and testing. At the time of this meeting, six clusters of galaxies have been detected and mapped via the inverse Compton scattering of the Cosmic Microwave Background radiation, also known as the Sunyaev-Zel'dovich Effect.

The Array for Microwave Background Anisotropy is a 7-element interferometer to be sited on Mauna Loa, Hawaii. The seven 1.2m telescopes are mounted on a 6-meter platform, and operates at 3mm wavelength. At the time of this meeting, the telescope is under construction at the Vertex factory in Germany. It is due to be delivered in the middle of 2004. A 2-element prototype instrument has already been deployed to Mauna Loa where initial tests are underway.

We present "on-the-fly" maps of CO (1–0) and CO (2–1) in the barred spiral galaxy M83. The entire optical disk is filled with CO emission in both lines, including interarm regions. For a "standard" conversion factor the total molecular mass is 2.5 × 109 M⊙, 4% of the total dynamical mass. Molecular gas constitutes 80% of total gas mass within the inner 10' and 30% overall. CO (1–0) emission and 21 cm continuum emission are extremely well correlated spatially in regions where H2 dominates the gas surface density. The spatial correlation between CO (1–0) and 100 μm emission is not as good. While the kinematics of the outer H I disk is severely nonaxisymmetrically perturbed, the kinematics of the CO disk and inner H I disk is well behaved and circular. The molecular disk appears to have a distinct hard edge at 5'. The hard edge is accompanied by a steep decline in the total gas surface density at that radius, although the H I does continue outward at a lower level. This edge is coincident with the onset of strong warping of the outer disk. The mean ratio of CO (2–1)/CO (1–0) emission is ~1, high by Galactic standards. Peaks in this ratio in interarm regions suggest that the CO emission is optically thin there, among other possibilities. Thus, M83 is unusual in that it has a relatively axisymmetric, almost entirely molecular, inner 10' gas disk surrounded by a warped, entirely atomic, outer gas disk. A sharp discontinuity separates the inner and outer gas disks. This kind of gas distribution is not seen in other late-type, gas-rich spirals.

We present "on-the-fly," fully sampled maps of CO(1–0) in the central 15' of the spiral galaxy IC 342. In addition to the bright CO nuclear peak, there is a prominent CO 2' × 5' bar and an extensive CO disk. The bar and nucleus contain 30% of the total observed CO emission in IC 342. Beyond the bar the CO disk contains two spiral arms, which coincide with the two inner optical arms. The substantial interarm CO component within this inner region has a mean surface density of 8 M⊙ pc-2, close to the mean surface density of 10 M⊙ pc-2, that extends to a radius of 7' (4 kpc). The total inferred H2 mass is 7 × 108 M⊙, which is 30% of the total H I mass. We combine the CO data with VLA H I maps to obtain a map of the total gas surface density (ΣH I + Σ) in IC 342. The gas surface density shows a centrally peaked disk, dominated by H2 to a radius of 5' (3 kpc). Spiral arms run continuously from the inner to outer galaxy, transitioning smoothly from predominantly molecular in the inner galaxy to predominantly atomic at large radii. On a global scale, the gas surface density is spatially correlated with optical spiral arm structure. On 1' (600 pc) scales the disk displays bar and arm asymmetries, azimuthal displacements of CO and H I emission, and structure that becomes increasingly complex with increasing galactic radii. We find an excellent correlation between 21 cm radio continuum and the total gas surface density.

The Heinrich Hertz Telescope (HHT), with the associated instrumentation, and the Gene Frazier Enclosure form a facility dedicated to submillimeter-wavelength radio astronomy that is operated by the Submillimeter Telescope Observatory (SMTO). It is located at 3200 m altitude on Mount Graham in eastern Arizona. The reflector has a diameter of 10 m and an accuracy of 12 μm rms. It is composed of 60 panels, made of aluminum honeycomb with carbon fiber reinforced plastic (CFRP) skins. The absolute pointing accuracy is about 2'', with a tracking accuracy of better than 1''. The corotating enclosure is opened during observations. The reflector support structure is made of low-expansion material (CFRP and invar steel). This allows the use of the telescope during daytime, under differential warming by the Sun, without a measurable decrease in its efficiency or pointing stability. We describe the salient features of the site and the enclosure, the structural design, the holographic measurement of the reflector surface, and the optics layout of the telescope. We also present some results of the pointing and efficiency calibration. Finally, a few examples of early astronomical results illustrate the potential of the telescope for high-quality submillimeter-wavelength astronomy.

The subtitle of this group of ten original essays by fifteen authors provides the focus and organization of the contents of this book edited by Thomas R. Leinbach and Cristina Capineri. These essay...

An active reflective component can change its focal length by physically deforming its reflecting surface. Such elements exist at small apertures, but have yet to be fully realized at larger apertures. This paper presents the design and initial results of a large-aperture active mirror constructed of a composite material called carbon fiber reinforced polymer (CFRP). The active CFRP mirror uses a novel actuation method to change radius of curvature, where actuators press against two annular rings placed on the mirror’s back. This method enables the radius of curvature to increase from 2000mm to 2010mm. Closed-loop control maintains good optical performance of 1.05 waves peak-to-valley (with respect to a HeNe laser) when the active CFRP mirror is used in conjunction with a commercial deformable mirror.

The Naval Research Laboratory and Sandia National Laboratories have been actively researching the use of carbon fiber reinforced polymer material as optical elements in many optical systems. Active optical elements can be used to build an optical system capable of changing is optical zoom. We have developed a two-element optical system that uses a large diameter, thin-shelled carbon fiber reinforced polymer mirror, actuated with micro-positioning motors, and a high actuator density micro-electro-mechanical deformable mirror. Combined with a Shack-Hartmann wavefront sensor, we have optimized this actuated carbon fiber reinforced polymer deformable mirror's surface for use with a forthcoming reflective adaptive optical zoom system. In this paper, we present the preliminary results of the carbon fiber reinforced polymer deformable mirror's surface quality and the development of the actuation of it.

Adaptive or active elements can alter their shape to remove aberrations or shift focal points. Carbon fiber reinforced polymer (CFRP) material improves upon current active mirror materials, such as Zerodur, in several ways: low stiffness-to-weight ratio, very low hysteresis, and greater dynamic range of correction. In this paper, we present recent developments in CFRP mirror actuation, i.e., changing the mirror's shape in an accurate and repeatable fashion. Actuation methods are studied both theoretically, using finite element analysis, and experimentally, using interferometric testing. We present results using two annular rings to push against the mirror's back, producing a wavefront with less than 20 waves of total error. Applications for this work include active telescope secondaries, phase diversity, and adaptive zoom systems.

Thin-shelled composite mirrors have been recently proposed as both deformable mirrors for aberration correction and as variable radius of curvature mirrors for phase diversity, auto focus, and adaptive optical zoom. The requirements of actuation of a composite mirror far surpass those for MEMS deformable mirrors. This paper will discuss the development of a finite element model for a 0.2 meter carbon fiber reinforced polymer mirror for use as a variable radius of curvature mirror in conjunction with a MEMS deformable mirror for aberration correction.

Thin-shelled composite mirrors have been recently proposed as both deformable mirrors for aberration correction and as variable radius-of-curvature mirrors for adaptive optical zoom. The requirements on actuation far surpass those for other MEMS or micro-machined deformable mirrors. We will discuss recent progress on developing the actuation for these mirrors, as well as potential applications.

There is a controversy among rural development workers regarding the effect that roads have on the production of illicit drug crops. Do roads promote or discourage their production? This paper examines the effect of roads on illegal opium cultivation in northern Thailand. Accessibility indexes are developed at district levels. Relationships among the indexes and opium production are analysed. The results show a weak relationship between accessibility and production and lead to the conclusion that neither the location nor the amount of opium production is significantly related to the road network. The findings suggest that a complete assessment of the role of transportation in drug production will require a more detailed information base than presently exists. Data are needed from source countries that allow network modelling of drug flow, law enforcement strategies and economic constraints.

The SMT is a highly accurate telescope of 10 m diameter with a reflector quality of 15 μm rms and a pointing/tracking accuracy of 1 arcsec. It provides excellent performance at 350 μm, the shortest wavelength submillimeter atmospheric window. The SMT will be located on Mt. Graham, Arizona at an altitude of 3200 m. The performance of the SMT is attained through extensive use of carbon fiber reinforced plastic in the structure, allowing unimpaired use of the instrument under various environmental conditions. Both the site and the telescope design allow submillimeter observations during the day as well as the night. We summarize here the technical features of the telescope. The project organisation and the site characteristics have been described in the proceedings of the Kona Symposium (Baars, Krugel and Martin, 1989).

The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) is the first interferometer dedicated to studying the cosmic microwave background (CMB) radiation at 3mm wavelength. The choice of 3mm was made to minimize the contributions from foreground synchrotron radiation and Galactic dust emission. The initial configuration of seven 0.6m telescopes mounted on a 6-m hexapod platform was dedicated in October 2006 on Mauna Loa, Hawaii. Scientific operations began with the detection of a number of clusters of galaxies via the thermal Sunyaev-Zel'dovich effect. We compare our data with Subaru weak lensing data in order to study the structure of dark matter. We also compare our data with X-ray data in order to derive the Hubble constant., Comment: accepted for publication in ApJ (13 pages, 7 figures); a version with high resolution figures available at http://www.asiaa.sinica.edu.tw/~keiichi/upfiles/AMiBA7/pho_highreso.pdf

Presented is a poster presentation relating to the final assembly and testing of the Ultra Lightweight Telescope for Research in Astronomy, ULTRA [1]. The program is a 3-year Major Research Instrumentation (MRI) program funded by NSF. Objectives are to demonstrate carbon fiber reinforced plastic (CFRP) composite mirrors for ground-based optical telescopes. Presented will be final assembly of the telescope including the unique features of the system including the 27 kg primary mirror, hexapod secondary mirror control, motorized iris for the primary mirror cover. Also presented are results of the optical testing of the 0.4m mirrors used as developmental optics in the program.

CFRP (carbon fiber reinforced plastic) is an attractive material for fabrication of optical systems. The stiffness-to-weight ratio of CFRP is high, the coefficient of thermal expansion is low, the structure thermalizes rapidly, and many of the structural properties can be tailored to the application. We have used CFRP and CFRP-aluminum sandwich panels extensively in the structures of astronomical, optical telescopes up to 1.5m diameter aperture. In designing the optical structures, we have chosen some key fabrication techniques with CFRP that take advantage of the mechanical properties. This paper discusses the design and fabrication of 2 major telescope projects. The 1m ULTRA telescope has both the optics and the OTA fabricated from CFRP. This telescope has been recently installed at the SDSU Mt. Laguna Observatory near San Diego. A 1.4m telescope for the Naval Research Lab is being designed and fabricated at CMA. The optics, OTA, and the mount are all being fabricated using CFRP composites. The result is a lightweight structure which can be moved or deployed as necessary.

Presented are unique concepts for space telescopes and optics, based on carbon fiber reinforced polymer (CFRP) thin-shelled mirror technology. Thin-shell CFRP mirrors have been proven for IR and longer wavelengths and to a large extent, visible wavelength optics. The unique structural/mechanical and lightweight characteristics of thin shells open the design possibilities for advanced space telescopes with active/adaptive mirrors. Low weight and general ease of manufacturing of CFRP structures can result in reduced part-count and inexpensive lightweight telescopes for space applications. Three advanced mirror concepts will be presented in this paper, 1) Advanced stowage of thin-shell mirrors for segmented telescopes, 2) advanced deformable mirror concepts, and 3) simple and inexpensive fabrication concepts using simplified molding tools for space telescope mirrors. Also presented will be empirical data of CFRP thin-shell mirrors and composite structures produced supporting their use for space telescope applications.

The design, manufacture and testing of lightweight Carbon Fiber Reinforced Polymer (CFRP) converging spherical mirrors for the RICH-1 Cherenkov detector of LHCb are described. The mirrors have low areal density to minimize the amount of material in the path of traversing particles and need to be fluorocarbon compatible to avoid degradation in the C 4 F 10 radiator gas. The total area is about 2m 2 and high reflectivity (typically 90%) over the wavelength range 200-600nm is required.

The focus of the ULTRA Project is to develop and test Ultra-Lightweight Technology for Research applications in Astronomy. The ULTRA project is a collaborative effort involving the private firm Composite Mirror Applications, Inc (CMA) and 3 universities: University of Kansas, San Diego State University, and Dartmouth College. Funding for ULTRA is predominately from a NSF three year MRI program grant to CMA and KU with additional support from CMA, KU and SDSU. The goal of the ULTRA program is to demonstrate that a viable alternative exists to traditional glass mirror and steel telescope technology by designing, fabricating and testing a research telescope constructed from carbon fiber reinforced plastic (CFRP) materials. In particular, a 1m diameter, Cassegrain telescope optics set and optical tube assembly (OTA) are being designed and fabricated by CMA. The completed telescope will be deployed at SDSU's Mt Laguna Observatory in a refurbished structure (new dome and mount provided via KU and SDSU). We expect that a successful completion and testing of this project will lead to future use of CFRP technology in larger telescopes and segmented telescopes. This paper describes the OTA (optical tube assembly) that has been developed for the ULTRA project. The mirror technology is described in another paper in this conference. A poster describes the ULTRA project overview in more detail.

Presented are results of continuing optical mirror development program for the NSF ULTRA Telescope. Development of a 16-inch f/4.0 parabolic mirror has been undertaken to adequately define scale-up fabrication procedures for 1m and 1.4m mirrors. 16-inch mirrors have been produced to λ/15 rms ( λ=633nm) in the wavefront. These mirrors have been used to produce astronomical images in a Newtonian telescope and yielded quality optical images. Presented will be results of the fabrication of the 1m, f/3 parabolic primary mirror mandrel for the 1m ULTRA Telescope. Also presented will be lab test data and astronomical mages produced under the 16-inch program as well as test data from the replications from the f/3 1m parabola.

Under contract from the Cornell-Caltech Atacama Telescope Project (CCAT), Composite Mirror Applications, Inc. (CMA) has undertaken a feasibility design study for the use of Carbon Fiber Reinforced Plastic (CFRP) panels in forming the primary mirror surface. We review some of the past projects using CFRP panel technology for millimeter and submillimeter wavelength radio astronomy telescopes. Pros and cons of the technology are discussed. A particular panel configuration was proposed and computer modeled with finite element analysis (FEA). The technology of replicated CFRP panels for short wavelength radio astronomical telescopes is mature and cost effective. For shorter wavelengths into the IR and visible, it is becoming a very attractive alternative to traditional, heavy glass or metal technologies.

Presented are results of a fabrication program to produce the Ring Imaging Cherenkov, RICH, mirror for the Alpha Magnetic Spectrometer, AMS-02, which is to be placed on the International Space Station. Composite Mirror Applications, Inc., CMA, in Tucson AZ was contracted by Carlo Gavazzi Space, CGS, to produce a conical mirror 1.3m diameter 0.5m in height, from high modulus carbon fiber, flight qualified composite materials, having an optical surface on the inside of the cone. The flight model mirror was completed to specification, yielding nearly 2m 2 of replicated optical surface area and weighs 8 kg. CMA measured the surface roughness and slope errors and the mirror dimensions were measured using a CMM at The University of Arizona's Instrument Shop. The results show the mirror meets conformance to the required specifications. The RICH mirror is currently undergoing flight testing and integration.

We present the technical status of the Ultra Lightweight Telescope for Research in Astronomy (ULTRA) program. The program is a 3-year Major Research Instrumentation (MRI) program funded by NSF. The MRI is a collaborative effort involving Composite Mirror Applications, Inc. (CMA), University of Kansas, San Diego State University and Dartmouth College. Objectives are to demonstrate the feasibility of carbon fiber reinforced plastic (CFRP) composite mirror technology for ground-based optical telescopes. CMA is spearheading the development of surface replication techniques to produce the optics, fabricating the 1m glass mandrel, and constructing the optical tube assembly (OTA). Presented will be an overview and status of the 1-m mandrel fabrication, optics development, telescope design and CFRP telescope fabrication by CMA for the ULTRA Telescope.

AMiBA consists of a 90 GHz interferometric array telescope with dishes ranging in size from 0.3 to 2.4 meter in diameter, mounted on a 6-meter fully steerable platform. The dishes are attached to the receivers, which are mounted on a platform controlled by a six degree of freedom hexapod mount. The hexapod mount is a parallel connection manipulator also called Stewart Platform. The basic reference for this mechanism is a paper by Stewart. The Stewart Platform is a unique kinematically constrained work platform. It can be manipulated through the six degrees of freedom. The hexapod also provides better accuracy, rigidity, load to weight ratio and load distribution than a serial manipulator or traditional manipulator. The advantages of the hexapod shows that it is a great choice for the AMiBA project. Vertex Antennentechnik GmbH fabricates the hexapod. Testing has started in Germany. The telescope will be delivered in the summer of 2004. The 6m in diameter hexagonal platform is made of carbon fiber reinforced plastics (CFRP) and consists of seven pieces of three different unique types. The platform can be disassembled and fits in a container for transportation. The mounting plane flatness is an important issue for the platform assembly. The deflection angle of the mounting plane relative to any other mounting position must be less than 20 arcsec. Meanwhile, the platform must endure a loading of 3 tons. The platform has been built by Composite Mirror Applications, Inc. (CMA) in Tucson, and mounted on the Hexapod in Germany. This report describes the design and testing of platform and mount for the AMiBA telescope.

A submillimeter Fourier Transform Spectrometer of the Martin-Puplett type was constructed and deployed to the geographical South Pole in 2001. The instrument operates from about 300 GHz to almost 2 THz and was used over winter to acquire atmospheric spectra with resolution as fine as 250 MHz. The main motivation for constructing and deploying this FTS was for astronomical site testing, but the obtained spectra can have important secondary uses in atmospheric science and transmission model validation. Some preliminary, low spectral resolution site testing results are presented here.

AMiBA is a 90 GHz interferometric array of the ASIAA (Academia Sinica, Institue of Astronomy and Astrophysics). It will make a detailed study of the polarization of the CMB anisotropy; it will also undertake a survey of Sunyaev-Zel’dovich clusters. It is under construction at present, with an expected completion date of late 2003.

The Academia Sinica, Institute for Astronomy and Astrophysics (ASIAA) is building two antennas to be added to the six antennas of the Sub-Millimeter Array (SMA) of the Smithsonian Astrophysical Observatory (SAO). The antennas have been designed at SAO and are currently under construction at Mauna Kea. ASIAA's two antennas are made in Taiwan from parts manufactured locally and imported from Europe and from the USA. This report will focus on the manufacturing and testing of 2 major components: the alidade and the reflector. We will emphasize the work done on the composite parts used in the 6- meter reflectors, namely the carbon fiber tubes for the backup structure, the carbon fiber legs of the quadrupod and the composite central hub. We will discuss the modal testing and pointing tests of the antennas. Finally this report will show how the Taiwanese industry was able to respond to the high manufacturing standards required to build sub-millimeter antennas. The design and manufacturing capabilities of the Aeronautical Research Laboratories and China Shipbuilding Corporation have made possible the construction of the telescopes in Taiwan.

We present a unique hexapod platform array for the new Taiwanese AMIBA project. AMIBA is a 90 GHz radio interferometric array consisting of 19 elements mounted on a roughly 10 m diameter platform. A hexapod mount is used to steer this platform. The resulting design is lightweight in comparison to a more conventional mount. The design goals of pointing stability, platform accuracy and reduced cost can be met with this design. A metrology system for pointing is proposed for inclusion in the design.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This is to report on our progress and current status of the Sub-Millimeter Array (SMA) project in Taiwan. In particular, we will describe the development of the SMA receiver systems. The SMA is the first major instrumentation project in the Taiwanese astronomical research community. The primary design and development of the SMA receiver system has been carried out in the receiver laboratory at the Smithsonian Astrophysical Observatory (SAO). We have undertaken the system assembly, integration and testing, and the task to fabricate the superconductor-insulator-superconductor (SIS) mixers used for our SMA receivers. The system will be initially equipped with two SIS receiver modules to cover 176 - 256 GHz and 250 - 350 GHz bands, followed with a third band of 600 - 720 GHz. The receiver system will be installed in the antenna in the mid-2000. The major milestone for this project is to ship the antennas to Mauna Kea, Hawaii to join the rest of the SMA for testing interferometric observation before the end of the year 2000.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The Heinrich Hertz Telescope is a radio telescope dedicated to the observation of submillimeter wavelength radiation from celestial sources. It is a Cassegrain telescope with a diameter of 10 m and a reflector accuracy of about 17 micrometer, yielding an excellent performance at 350 micrometer, the shortest wavelength transmitted through the atmosphere. The reflector panels and the backup structure employ carbon-fiber reinforced plastic as basic material to achieve a lightweight, stiff construction with a very small coefficient of thermal expansion. This enables us to maintain full performance of the telescope in day time under solar illumination of the structure. In this paper, we describe the structural and material characteristics of the telescope. We also describe the holographic method which enables a measurement and setting of the reflector panels to an accuracy of 10 micrometer. The telescope is located on Mt. Graham in Eastern Arizona at an altitude of 3250 m, providing good submillimeter observing conditions, especially in the winter months. This is a collaborative effort of the Max-Planck- Institut fur Radioastronomie, Bonn, Germany and Steward Observatory, University of Arizona, Tucson, AZ.

We report on the status of SIS mixers being constructed at the Institute of Astronomy and Astrophysics, Academia Sinica. These mixers will later be integrated into the receiver systems used on the ASIAA supplied antennas for the SMA project. We have reproduced the SAO design for these mixers at the 200 GHz band. We achieve acceptable noise performance across the tuning band of the mixers.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The Steward Observatory of the University of Arizona and the Max-PlanckInstitut fur Radioastronomie (Germany) have collaborated on the construction and operation of a dedicated submillimeter telescope facility. The Submillimeter Telescope Observatory (SMTO) has been formed to operate the facility for the two partner institutions. The facility is located at an altitude of 3200 meters on Mt. Graham in southeast Arizona. The 10 m diameter telescope is an alt-azimuth mounted f/13.8 Cassegrain homology telescope with two Nasmyth foci. The telescope has diffraction limited performance at a wavelength of 300 microns. During the last year, the telescope reflector surface has been adjusted to 20 microns rms and initial astronomical observations have begun.

We report the first extragalactic detection of the neutral carbon [CI] 3P2-3P1 fine structure line at 809 GHz. The line was observed towards M82 simultaneously with the 3P1-3P0 line at 492 GHz, providing a precise measurement of the J=2-1/J=1-0 integrated line ratio of 0.96 (on a [K km s^-1] -scale). This ratio constrains the [CI] emitting gas to have a temperature of at least 50 K and a density of at least 10^4 cm^-3. Already at this minimum temperature and density, the beam averaged CI-column density is large, 2.1 10^18 cm^-2, confirming the high CI/CO abundance ratio of approximately 0.5 estimated earlier from the 492 GHz line alone. We argue that the [CI] emission from M82 most likely arises in clouds of linear size around a few pc with a density of about 10^4 cm^-3 or slightly higher and temperatures of 50 K up to about 100 K., 4 pages, 2 figures, ApJL in press, postscript also available at ftp://apollo.ph1.uni-koeln.de/pub/stutzki/m82_pap.ps.gz e-mail-contact:stutzki@ph1.uni-koeln.de

Thin-shelled composite mirrors have been recently proposed for use as deformable mirrors in optical systems. Large-diameter deformable composite mirrors can be used in the development of active optical zoom systems. We present the fabrication, testing, and modeling of a prototype 0.2 m diameter carbon fiber reinforced polymer mirror for use as a deformable mirror. In addition, three actuation techniques have been modeled and will be presented.

To exploit the potential of submillimeter astronomy, the Submillimeter Telescope (SMT) will be located at an altitude of 3178 meters on Emerald Peak 75 miles northeast of Tucson in Southern Arizona. The instrument is an altazimuth mounted f/13.8 Cassegrain homology telescope with two Nasmyth and bent Cassegrain foci. It will have diffraction limited performance at a wavelength of 300 microns and an operating overall figure accuracy of 15 microns rms. An important feature of the SMT is the construction of the primary and secondary reflectors out of aluminum-core CFRP face sheet sandwich panels, and the reflector backup structure and secondary support out of CFRP structural elements. This modern technology provides both a means for reaching the required precision of the SMT for both night and day operation (basically because of the low coefficient of thermal expansion and high strength-to-weight ratio of CFRP) and a potential route for the realization of lightweight telescopes of even greater accuracy in the future. The SMT will be the highest accuracy radio telescope ever built (at least a factor of 2 more accurate than existing telescopes). In addition, the SMT will be the first 10 m-class submillimeter telescope with a surface designed for efficient measurements at the important 350 microns wavelength atmospheric window.

This paper draws attention to the potential for use of telescopes now under construction or planned for the near future as part of the Mt. Graham International Observatory, located in the Pinaleño Mts. east of Tucson, Arizona, for interferometer observations at mm-and submm-wavelengths. The Submillimeter Telescope (SMT) should be completed by early 1993. A collaboration between the Max-Planck-Institut für Radioastronomie and Steward Observatory, the SMT is a high-precision 10-m diameter telescope which will be useful for short-wavelength VLBI observations. A large optical telescope, consisting of two 8.4-m diameter mirrors on a common mount, is in the early design stages. When completed, it will provide for short-baseline (approx. 20-m) interferometry between the two optical mirrors, as well as interferometry with the SMT over baselines of a few hundred meters.

The concept of simultaneous multifrequency continuum observations, successfully tested on Comet Hyakutake, was applied to Comet Hale-Bopp, using the Heinrich Hertz Submillimeter Telescope (HHT) with the four color bolometer between 250 and 870 GHz, the IRAM 30m telescope at 240 Ghz, the MPIfR 100-m telescope at 32 GHz, and the IRAM interferometer near 90 and 240 GHz. Near-simultaneous measurements were done between February 15 and April 26, 1997, mainly concentrated in mid March shortly before perigee of the comet.

We have mapped the CO J=3-2 emission in the inner 60″ (1500 pc) of the nearby SBb(s) pec galaxy Maffei 2 with the Caltech Submillimeter Observatory (CSO). The morphology of the CO (3-2) matches that seen in C0 (1-0) interferometric maps, possessing a barlike structure that is coincident with the morphology of radio continuum and mid-infrared observations of the extended starburst region. By assuming that the observed CO (3-2) emission is optically thin we set lower limits to the molecular column densities along the bar of N H2 ≥6-9×10 20 cm -2 and to the total molecular mass of M H2 ≥6×10 6 M ○ .

Extragalactic NH{sub 3} is successfully imaged with 5-arcsec resolution using the VLA. Essentially all the single-dish flux is recovered in the interferometer maps. The hot gas (above 70 K), inferred from single-dish NH{sub 3} line-intensity ratios, appears to be closely associated with the innermost portions of the nuclear bar seen in CO. Small-scale anticorrelation of the NH{sub 3} emission with the central thermal radio continuum emission is likely to be due to heating and photoionization effects. 22 refs.

Observations of the J = 3-2 transitions of (C-12)O and (C-13)O in the starburst galaxy M82 are reported. The (C-12)O J = 3-2 transition in the nuclear region is detected and mapped at 22-arcsec resolution. The high main beam brightness temperature of the line, 6.4 K, when compared to the J = 1-0 and J = 2-1 intensities, requires a hot moderately optically thin gas. There are about 10 to the 8th solar masses of warm molecular gas within a radius of 360 pc of M82. The low optical depths and high densities required to excite the J = 3-2 transition may imply sheetlike or filamentary clumping. 31 refs.

As the strategic importance of the Third World increases, more emphasis is being placed on operations short of war in underdevloped nations. One potential instrument for promoting stability in a region, thereby advancing U.S. interests, is developmental assistance in the form of infrastructure planning, design and construction. This study seeks to examine nation building as an instrument of U.S. strategy in terms of benefits versus liabilities and to examine conditions that must exist for nation building to be successful. It provides a general overview of the current U.S. nation building posture and players. The purpose for examining nation building as an instrument of U.S. strategy and the current U.S. posture and structure is to identify a set of pitfalls that have derailed past programs; identify: the challenges that must be addressed to initiate new programs; a set of principles for success in nation building program; and to put forward a general concept and organizational structure for future nation building programs with emphasis on the engineer contribution to this effort. Keywords: Military assistance; Nation building.

We introduce a new spectroscopic method at radio frequencies to measure the temperature of giant cloud complexes in external galaxies. We have detected the λ = 1.3 cm J, K = 2, 2 inversion transition of NH3 in the nucleus of the galaxy IC342. This result, taken together with our previous detection of the J, K = 1, 1 transition1 allows us to deduce a kinetic temperature of 50±15 K and an equivalent size scale of at least 25 pc for the molecular gas. The results are consistent with line formation in the nucleus where very active star formation is taking place.

The J = 3-2 CO line is detected for the first time in an external galaxy, in the nearby spiral IC 342. It is shown that in contrast to the J = 1-0 CO line, which favors optically thick and cool gas, the J = 3-2 CO line can be used to study a hot component in extragalactic nuclear environment. Limited mapping results suggest that the J = 3-2 CO emission arises from the same regions as the J = 1-0 CO emission. It is therefore likely that hot gas and strong star-formation activities are closely associated with the central molecular gas bar. 20 references.

Resultats d'observation de M17 dans la raie d'emission J=7→6 de CS a 874 μm, ainsi que dans la raie J=4→3 en des points selectionnes. On en deduit que la densite dans le cœur est superieure a 10 6 cm −3 et que le cœur peut etre resolu en plusieurs condensations, chacune ayant une dimension ∼0,7 pc et une masse ∼1000 M ○.