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Gorenstein, Paul

Publications and source records attributed to Gorenstein, Paul.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Transient Astrophysics Probe: White Paper

The Transient Astrophysics Probe (TAP) is a wide-field multi-wavelength transient mission proposed for flight starting in the late 2020s. The mission instruments include unique ``Lobster-eye'' imaging soft X-ray optics that allow an approximately 1600-degrees-squared Field of View (FoV); a high sensitivity, 1-degree-squared FoV soft X-ray telescope; a 1-degree-squared FoV Infrared telescope with bandpass 0.6 to 3 microns; and a set of 8 NaI gamma-ray detectors. TAP's most exciting capability will be the observation of tens per year of X-ray and Infrared counterparts of gravitational waves (GWs) involving stellar-mass black holes and neutron stars detected by LIGO (Laser Interferometer Gravitational-Wave Observatory ) / Virgo / KAGRA (Kamioka (Japan) Gravitational Wave Detector) / LIGO-India, and possibly several per year X-ray counterparts of GWs from supermassive black holes, detected by LISA (Laser Interferometer Space Antenna) and Pulsar Timing Arrays. TAP will also discover hundreds of X-ray transients related to compact objects, including tidal disruption events, supernova shock breakouts, and Gamma-Ray Bursts from the epoch of reionization.

Camp, Jordan↗
NASA NTRS2010

High-Resolution X-Ray Telescopes

Fundamental needs for future x-ray telescopes: a) Sharp images => excellent angular resolution. b) High throughput => large aperture areas. Generation-X optics technical challenges: a) High resolution => precision mirrors & alignment. b) Large apertures => lots of lightweight mirrors. Innovation needed for technical readiness: a) 4 top-level error terms contribute to image size. b) There are approaches to controlling those errors. Innovation needed for manufacturing readiness. Programmatic issues are comparably challenging.

ODell, Stephen L.↗
NASA NTRS2010

Focusing X-Ray Telescopes

During the half-century history of x-ray astronomy, focusing x-ray telescopes, through increased effective area and finer angular resolution, have improved sensitivity by 8 orders of magnitude. Here, we review previous and current x-ray-telescope missions. Next, we describe the planned next-generation x-ray-astronomy facility, the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility, Generation X. Its scientific objectives will require very large areas (about 10,000 sq m) of highly-nested, lightweight grazing-incidence mirrors, with exceptional (about 0.1-arcsec) resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.

O'Dell, Stephen↗
NASA NTRS2007

A Hard X-Ray Telescope Science Enhancement Package for the Constellation X-Ray Mission

Details of a hard-x-ray science enhancement package for the Constellation-X mission are presented. A scientific case is made for the inclusion of such an instrument on the planned mission and a detailed design is presented that will satisfy science requirements yet fall within the ground rules for enhancement packages: a cost of less than $100M and a mass of no more than 100 kg.

Ramsey, Brian↗
NASA NTRS2007

A Hard-X-Ray Telescope Science Enhancement Package for the Constellation-X Mission

We present a science enhancement package (SEP) for NASA's planned Constellation-X mission submitted in response to a call for white papers. The call solicited proposals for either extending the bandwidth of Con-X to higher energies or enhancing the low-energy spectral resolution. The ground rules were that enhancement package should cost no more than $100M and weigh no more than 100 kg. The nickel-replicated-optics team responded with a stand-alone hard-x-ray telescope SEP concept. This consisted of two mirror modules, each with approximately 70 multilayer and iridium-coated shells, and two corresponding cadmium-zinc-telluride-based focal plane detectors. Addition of this package permits measurement of the hard-x-ray continuum up to 30-40 keV, which is essential for a quantitative measurement of the spectrum of gravitationally broadened iron lines that appear in the spectra of many black hole candidates. Full details of the instrument will be presented showing trades in energy bandwidth and effective area together with the full science justification for the enhancement package.

Ramsey, Brian↗
NASA NTRS2005

Development of High Resolution Hard X-Ray Telescope with Multi-Layer Coatings

This is the annual report for the third year of a three-year program. Previous annual reports have described progress achieved in the first and second years. The major objective of this program is the development of a focusing hard X-ray telescope with moderately high angular resolution, i.e. comparable to the telescopes of XMM-Newton. The key ingredients of the telescope are a depth graded multilayer coatings and electroformed nickel substrates that are considerably lighter weight than those of previous missions such as XMM-Newton, which have had conventional single metal layer reflective coatings and have operated at much lower energy X-rays. The ultimate target mission for this technology is the Hard X-Ray Telescope (HXT) of the Constellation X-Ray Mission. However, it is applicable to potential SMEX and MIDEX programs as well. We are building upon technology that has proven to be successful in the XMM-Newton and SWIFT missions. The improvements that we are adding are a significant reduction in mass without much loss of angular resolution and an order of magnitude extension of the bandwidth through the use of multilayer coatings. The distinctive feature of this approach compared to those of other hard X-ray telescope programs is that we expect the angular resolution to be superior than telescopes made by other methods thanks to the structural integrity of the substrates. They are thin walled complete cylinders of revolution with a Wolter Type 1 figure; the front half is a parabola, the rear half a hyperbola.

Gorenstein, Paul↗
NASA NTRS2004

Development of High Resolution Hard X-Ray Telescope with Multilayer Coatings

The major objective of this program is the development of a focusing hard X-ray telescope with moderately high angular resolution, i .e. comparable to the telescopes of XMM-Newton. The key ingredients of the telescope are a depth graded multilayer coatings and electroformed nickel substrates that are considerably lighter weight than those of previous missions such as XMM-Newton, which have had conventional single metal layer reflective coatings and have operated at much lower energy X-rays. The ultimate target mission for this technology is the Hard X-Ray Telescope (HXT) of the Constellation X-Ray Mission. However, it is applicable to potential SMEX and MIDEX programs as well.

Brinton, John C.↗
NASA NTRS2004

MAXIM: The Blackhole Imager

The Beyond Einstein Program in NASA's Office of Space Science Structure and Evolution of the Universe theme spells out the top level scientific requirements for a Black Hole Imager in its strategic plan. The MAXIM mission will provide better than one tenth of a microarcsecond imaging in the X-ray band in order to satisfy these requirements. We will overview the driving requirements to achieve these goals and ultimately resolve the event horizon of a supermassive black hole. We will present the current status of this effort that includes a study of a baseline design as well as two alternative approaches.

Gendreau, Keith↗
NASA NTRS2003

Development of High Resolution Hard X-Ray Telescope with Multilayer Coatings

The activities that occurred during the first year of the grant were: a) completed construction of the large multilayer deposition facility; b) Coated a large number of flat substrates and the interiors of cylindrical X-ray telescope shell substrates with uniform period and depth graded periods of tungsten-silicon (W/Is) bi-layers and other coatings; c) studied the influence of various factors affecting the quality of the multilayer coatings by measuring their reflection efficiency at 8 keV and higher energy X-rays.

Gorenstein, Paul↗
NASA NTRS2001

Hard X-Ray And Wide Focusing Telescopes

The development of a hard X-ray telescope requires new technology for both substrates and coatings. Our activities in these two areas were carried out virtually in parallel during most of the past few years. They are converging on the production of our first integral conical, substrate electroformed mirror that will be coated with a graded d-spacing multilayer. Its imaging properties and effective area will be measured in hard X-ray beams. We discuss each of these activities separately in the following two sections.

Gorenstein, Paul↗
NASA NTRS1999

Hard X-Ray and Wide Focusing Telescopes

The subject of this program are the development of two new type of X-ray telescopes, the wide field telescope, and the hard X-ray telescope.

Gorenstein, Paul↗
NASA NTRS1999

Research with Large Area Imaging X-Ray Telescope Sounding Rocket Program

We are engaged in a program to develop focussing hard X-ray telescopes in a double conical or Wolter 1 geometry that function up to 100 keV by employing small graze angles and multilayer coatings. Directly polished substrates are not an option because they are too thick to be nested efficiently. The only alternative is to fabricate the very thin substrates by replication. Our objective is the production of integral cylindrical substrates because they should result in better angular resolution than segmented foil geometries. In addition, integral cylinders would be more resistant to possible stress from deep multilayer coatings than segmented ones. Both electroforming of nickel (method of SkX, JET-X, and XMM) and epoxy replication are under consideration. Both processes can utilize the same types of mandrels and separation agents- While electroforming can produce substrates that are thin, the high density of the nickel may result in high weight optics for some missions. For convenience, experimentation with replication and coating is being carried out initially on flats. Our replication studies include trials with gold and carbon separation agents. This paper reports on our efforts with epoxy replicated optics.

Gorenstein, Paul↗
NASA NTRS1998

Hard X-Ray Telescope (HXT) with Simultaneous Multiwavelength Observing from UV to 1 MeV

The Hard X-Ray Telescope Mission Concept Study no longer exists as a possible independent mission. The grazing incidence multilayer telescopes, its major component, are now firmly attached to the Constellation X-Ray Mission. It was determined that the most efficient deployment of a hard X-ray (10 to 100 keV) focussing telescope system is observing simultaneously with a high throughput lower energy spectrometer, providing the rationale for merging with Constellation X. This configuration permits four nearly four decades in energy (.2 to 100 keV) of an object's emission spectrum to be studied simultaneously with good energy resolution. Furthermore, the probability of attaining an independent mission for a hard X-ray telescope system is extremely low.

Gorenstein, Paul↗
NASA NTRS1998

Hard X-Ray and Wide Focusing Telescopes

Studies are being carried out to compare the performance of several different separation materials used in the replication process. This report presents the results obtained during the second year of a program which consists of replicating smooth, thin substrates, depositing multilayer coatings upon them, and evaluating their performance. Replication and multilayer coatings are both critically important to the development of focussing hard X-ray telescopes that function up to 100 keV. The activities of the current year include extending the comparison between sputtered amorphous carbon and evaporated gold to include sputtered as well as evaporated gold. The figure of merit being the smoothness of the replica which has a direct effect on the specular reflectivity. These results were obtained with epoxy replication, but they should be applicable to electroformed nickel, the process we expect to use for the ultimate replicated optics.

Gorenstein, Paul↗
NASA NTRS1997

The Hard X ray Telescope Mission

The Hard X Ray Telescope (HXT) was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity and much better angular resolution in the 10100 keV band, and (3) higher sensitivity for detecting gamma ray lines of known energy in the 100 keV to 1 MeV band. The institutions collaborating in the study are: Smithsonian Astrophysical Observatory, Marshall Space Flight Center, Naval Research Laboratory, Goddard Space Flight Center, Argonne National Laboratory, Danish Space Research Institute, Osservatorio Astronomica di Brera (Merate), and Centre d'Etudes Spatiale des Rayonnements (Toulouse). The instrumentation includes several grazing incidence double conical telescopes with multilayer coatings that focus up to 100 keV and a single Laue crystal telescope that functions to 1 MeV. The detectors are CCDs, and germanium, and/or CdZnTe position sensitive arrays.

Gorenstein, Paul↗
NASA NTRS1996

The large area modular array of reflections (LAMAR)

The Large Area Modular Array of Reflectors (LAMAR) was selected as an attached payload for the Space Station Freedom in June 1989. It is a high throughput multiple X-ray telescope system that was capable of performing both imaging and dispersive spectroscopy measurements simultaneously. The LAMAR program was halted in 1990 when attached payloads were removed from the Space Station. A technical description of LAMAR is the main body of this report.

Gorenstein, Paul↗
NASA NTRS1994

Various Roentgen satellite (ROSAT) related studies

The first six months was spent obtaining ROSAT Survey data for as many Slew Survey sources as possible. ROSAT Survey (RASS) counterparts for 605 of the 819 Slew sources (or 75 percent). were found at MPE, providing RASS positions, fluxes, and hardness ratios. The positions were used immediately to confirm or reject proposed catalog identifications from SIMBAD and NED, and to begin a program of identifying new BL Lac objects with high efficiency. In the final six months of the award, extensive analysis were preformed on the RASS counterpart data at Cambridge screening Slew sources with multiple RASS counterparts (up to 23); extended sources and sources with large discrepancies between the RASS and Slew positions. The possibly highly absorbed sources were also studied. Finally, the RASS data has helped to identify optical counterparts to Slew Survey sources - BL Lacs stars, and 'blank fields'.

Stauffer, John R.↗