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Author name code: vanbeek
ADS astronomy entries on 2022-09-14
author:Van Beek, H. Frank
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Title: The Spectrometer/Telescope for Imaging X-rays (STIX)
Authors: Krucker, Säm; Hurford, G. J.; Grimm, O.; Kögl, S.;
Gröbelbauer, H. -P.; Etesi, L.; Casadei, D.; Csillaghy, A.; Benz,
A. O.; Arnold, N. G.; Molendini, F.; Orleanski, P.; Schori, D.; Xiao,
H.; Kuhar, M.; Hochmuth, N.; Felix, S.; Schramka, F.; Marcin, S.;
Kobler, S.; Iseli, L.; Dreier, M.; Wiehl, H. J.; Kleint, L.; Battaglia,
M.; Lastufka, E.; Sathiapal, H.; Lapadula, K.; Bednarzik, M.; Birrer,
G.; Stutz, St.; Wild, Ch.; Marone, F.; Skup, K. R.; Cichocki, A.; Ber,
K.; Rutkowski, K.; Bujwan, W.; Juchnikowski, G.; Winkler, M.; Darmetko,
M.; Michalska, M.; Seweryn, K.; Białek, A.; Osica, P.; Sylwester, J.;
Kowalinski, M.; Ścisłowski, D.; Siarkowski, M.; Stęślicki, M.;
Mrozek, T.; Podgórski, P.; Meuris, A.; Limousin, O.; Gevin, O.; Le
Mer, I.; Brun, S.; Strugarek, A.; Vilmer, N.; Musset, S.; Maksimović,
M.; Fárník, F.; Kozáček, Z.; Kašparová, J.; Mann, G.; Önel,
H.; Warmuth, A.; Rendtel, J.; Anderson, J.; Bauer, S.; Dionies, F.;
Paschke, J.; Plüschke, D.; Woche, M.; Schuller, F.; Veronig, A. M.;
Dickson, E. C. M.; Gallagher, P. T.; Maloney, S. A.; Bloomfield, D. S.;
Piana, M.; Massone, A. M.; Benvenuto, F.; Massa, P.; Schwartz, R. A.;
Dennis, B. R.; van Beek, H. F.; Rodríguez-Pacheco, J.; Lin, R. P.
2020A&A...642A..15K Altcode:
<BR /> Aims: The Spectrometer Telescope for Imaging X-rays (STIX)
on Solar Orbiter is a hard X-ray imaging spectrometer, which
covers the energy range from 4 to 150 keV. STIX observes hard X-ray
bremsstrahlung emissions from solar flares and therefore provides
diagnostics of the hottest (⪆10 MK) flare plasma while quantifying
the location, spectrum, and energy content of flare-accelerated
nonthermal electrons. <BR /> Methods: To accomplish this, STIX applies
an indirect bigrid Fourier imaging technique using a set of tungsten
grids (at pitches from 0.038 to 1 mm) in front of 32 coarsely pixelated
CdTe detectors to provide information on angular scales from 7 to 180
arcsec with 1 keV energy resolution (at 6 keV). The imaging concept of
STIX has intrinsically low telemetry and it is therefore well-suited
to the limited resources available to the Solar Orbiter payload. To
further reduce the downlinked data volume, STIX data are binned on
board into 32 selectable energy bins and dynamically-adjusted time
bins with a typical duration of 1 s during flares. <BR /> Results:
Through hard X-ray diagnostics, STIX provides critical information
for understanding the acceleration of electrons at the Sun and their
transport into interplanetary space and for determining the magnetic
connection of Solar Orbiter back to the Sun. In this way, STIX serves
to link Solar Orbiter's remote and in-situ measurements.
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Title: The spectrometer telescope for imaging x-rays on board the
Solar Orbiter mission
Authors: Benz, A. O.; Krucker, S.; Hurford, G. J.; Arnold, N. G.;
Orleanski, P.; Gröbelbauer, H. -P.; Klober, S.; Iseli, L.; Wiehl,
H. J.; Csillaghy, A.; Etesi, L.; Hochmuth, N.; Battaglia, M.;
Bednarzik, M.; Resanovic, R.; Grimm, O.; Viertel, G.; Commichau, V.;
Meuris, A.; Limousin, O.; Brun, S.; Vilmer, N.; Skup, K. R.; Graczyk,
R.; Stolarski, M.; Michalska, M.; Nowosielski, W.; Cichocki, A.;
Mosdorf, M.; Seweryn, K.; Przepiórka, A.; Sylwester, J.; Kowalinski,
M.; Mrozek, T.; Podgorski, P.; Mann, G.; Aurass, H.; Popow, E.;
Onel, H.; Dionies, F.; Bauer, S.; Rendtel, J.; Warmuth, A.; Woche,
M.; Plüschke, D.; Bittner, W.; Paschke, J.; Wolker, D.; Van Beek,
H. F.; Farnik, F.; Kasparova, J.; Veronig, A. M.; Kienreich, I. W.;
Gallagher, P. T.; Bloomfield, D. S.; Piana, M.; Massone, A. M.;
Dennis, B. R.; Schwarz, R. A.; Lin, R. P.
2012SPIE.8443E..3LB Altcode:
The Spectrometer Telescope for Imaging X-rays (STIX) is one of 10
instruments on board Solar Orbiter, a confirmed Mclass mission of the
European Space Agency (ESA) within the Cosmic Vision program scheduled
to be launched in 2017. STIX applies a Fourier-imaging technique
using a set of tungsten grids (at pitches from 0.038 to 1 mm) in
front of 32 pixelized CdTe detectors to provide imaging spectroscopy
of solar thermal and non-thermal hard X-ray emissions from 4 to 150
keV. The status of the instrument reviewed in this paper is based on
the design that passed the Preliminary Design Review (PDR) in early
2012. Particular emphasis is given to the first light of the detector
system called Caliste-SO.
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Title: The Reuven Ramaty High-Energy Solar Spectroscopic Imager
(RHESSI)
Authors: Lin, R. P.; Dennis, B. R.; Hurford, G. J.; Smith, D. M.;
Zehnder, A.; Harvey, P. R.; Curtis, D. W.; Pankow, D.; Turin, P.;
Bester, M.; Csillaghy, A.; Lewis, M.; Madden, N.; van Beek, H. F.;
Appleby, M.; Raudorf, T.; McTiernan, J.; Ramaty, R.; Schmahl, E.;
Schwartz, R.; Krucker, S.; Abiad, R.; Quinn, T.; Berg, P.; Hashii,
M.; Sterling, R.; Jackson, R.; Pratt, R.; Campbell, R. D.; Malone,
D.; Landis, D.; Barrington-Leigh, C. P.; Slassi-Sennou, S.; Cork, C.;
Clark, D.; Amato, D.; Orwig, L.; Boyle, R.; Banks, I. S.; Shirey,
K.; Tolbert, A. K.; Zarro, D.; Snow, F.; Thomsen, K.; Henneck,
R.; Mchedlishvili, A.; Ming, P.; Fivian, M.; Jordan, John; Wanner,
Richard; Crubb, Jerry; Preble, J.; Matranga, M.; Benz, A.; Hudson,
H.; Canfield, R. C.; Holman, G. D.; Crannell, C.; Kosugi, T.; Emslie,
A. G.; Vilmer, N.; Brown, J. C.; Johns-Krull, C.; Aschwanden, M.;
Metcalf, T.; Conway, A.
2002SoPh..210....3L Altcode:
RHESSI is the sixth in the NASA line of Small Explorer (SMEX)
missions and the first managed in the Principal Investigator mode,
where the PI is responsible for all aspects of the mission except
the launch vehicle. RHESSI is designed to investigate particle
acceleration and energy release in solar flares, through imaging and
spectroscopy of hard X-ray/gamma-ray continua emitted by energetic
electrons, and of gamma-ray lines produced by energetic ions. The
single instrument consists of an imager, made up of nine bi-grid
rotating modulation collimators (RMCs), in front of a spectrometer
with nine cryogenically-cooled germanium detectors (GeDs), one behind
each RMC. It provides the first high-resolution hard X-ray imaging
spectroscopy, the first high-resolution gamma-ray line spectroscopy,
and the first imaging above 100 keV including the first imaging of
gamma-ray lines. The spatial resolution is as fine as ∼ 2.3 arc sec
with a full-Sun (≳ 1°) field of view, and the spectral resolution
is ∼ 1-10 keV FWHM over the energy range from soft X-rays (3 keV)
to gamma-rays (17 MeV). An automated shutter system allows a wide
dynamic range (>10<SUP>7</SUP>) of flare intensities to be handled
without instrument saturation. Data for every photon is stored in a
solid-state memory and telemetered to the ground, thus allowing for
versatile data analysis keyed to specific science objectives. The
spin-stabilized (∼ 15 rpm) spacecraft is Sun-pointing to within ∼
0.2° and operates autonomously. RHESSI was launched on 5 February
2002, into a nearly circular, 38° inclination, 600-km altitude orbit
and began observations a week later. The mission is operated from
Berkeley using a dedicated 11-m antenna for telemetry reception and
command uplinks. All data and analysis software are made freely and
immediately available to the scientific community.
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Title: High-Energy Solar Spectroscopic Imager (HESSI) Small Explorer
mission for the next (2000) solar maximum
Authors: Lin, Robert P.; Hurford, Gordon J.; Madden, Norman W.;
Dennis, Brian R.; Crannell, Carol J.; Holman, Gordon D.; Ramaty,
Reuven; von Rosenvinge, Tycho T.; Zehnder, Alex; van Beek, H. Frank;
Bornmann, Patricia L.; Canfield, Richard C.; Emslie, A. Gordon; Hudson,
Hugh S.; Benz, Arnold; Brown, John C.; Enome, Shinzo; Kosugi, Takeo;
Vilmer, Nicole; Smith, David M.; McTiernan, Jim; Hawkins, Isabel;
Slassi-Sennou, Said; Csillaghy, Andre; Fisher, George; Johns-Krull,
Chris; Schwartz, Richard; Orwig, Larry E.; Zarro, Dominic; Schmahl,
Ed; Aschwanden, Markus; Harvey, Peter; Curtis, Dave; Pankow, Dave;
Clark, Dave; Boyle, Robert F.; Henneck, Reinhold; Michedlishvili,
Akilo; Thomsen, K.; Preble, Jeff; Snow, Frank
1998SPIE.3442....2L Altcode:
The primary scientific objective of the High Energy Solar Spectroscopic
Imager (HESSI) Small Explorer mission selected by NASA is to investigate
the physics of particle acceleration and energy release in solar
flares. Observations will be made of x-rays and (gamma) rays from
approximately 3 keV to approximately 20 MeV with an unprecedented
combination of high resolution imaging and spectroscopy. The HESSI
instrument utilizes Fourier- transform imaging with 9 bi-grid rotating
modulation collimators and cooled germanium detectors. The instrument
is mounted on a Sun-pointed spin-stabilized spacecraft and placed
into a 600 km-altitude, 38 degrees inclination orbit.It will provide
the first imaging spectroscopy in hard x-rays, with approximately
2 arcsecond angular resolution, time resolution down to tens of ms,
and approximately 1 keV energy resolution; the first solar (gamma)
ray line spectroscopy with approximately 1-5 keV energy resolution;
and the first solar (gamma) -ray line and continuum imaging,with
approximately 36-arcsecond angular resolution. HESSI is planned for
launch in July 2000, in time to detect the thousands of flares expected
during the next solar maximum.
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Title: The High Energy Solar Spectroscopic Imager (HESSI): A Small
Explorer for the Start of the New Millennium
Authors: Holman, G. D.; Lin, R. P.; Dennis, B. R.; Crannell, C. J.;
Ramaty, R. R.; Rosenvinge, T. T.; Canfield, R. C.; Emslie, A. G.;
Hudson, H. S.; Hurford, G. J.; Madden, N. W.; van Beek, H. F.; Benz,
A.; Bornmann, P. L.; Brown, J. C.; Enome, S.; Kosugi, T.; Vilmer,
N.; Zehnder, A.
1997AAS...191.7416H Altcode: 1997BAAS...29R1326H
The High Energy Solar Spectroscopic Imager (HESSI) has been selected
for launch in mid 2000, at the peak of the solar activity cycle. The
primary scientific objective of HESSI is to understand particle
acceleration and explosive energy release in the magnetized plasma at
the Sun. HESSI will provide the first high-spectral-resolution x-ray and
gamma -ray images of the Sun. It will obtain the first imaging above
100 keV, the first imaging of solar gamma -ray lines, and the first
high-resolution spectroscopy of solar gamma -ray lines, including the
first determination of line shapes. In two years HESSI is expected to
obtain observations of tens of thousands of microflares, thousands of
hard x-ray flares, and of order a hundred gamma -ray line flares. HESSI
will also monitor and provide high-spectral-resolution observations of
cosmic and terrestrial hard x-ray and gamma -ray transients, as well
as imaging of the Crab Nebula. HESSI's high spectral, spatial, and
temporal resolution and dynamic range will allow the first detailed
studies of the evolution of both accelerated particles and hot,
thermal plasma in solar flares.
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Title: The High Energy Solar Spectroscopic Imager - HESSI
Authors: Dennis, B. R.; Crannell, C. J.; Holman, G. D.; Ramaty,
R.; von Rosenvinge, T. T.; Benz, A.; Bornmann, P. L.; Brown, J. C.;
Canfield, R. C.; Emslie, A. G.; Enome, S.; Kosugi, T.; Hudson, H. S.;
Hurford, G. J.; Lin, R. P.; Ling, J. C.; Madden, N. W.; van Beek,
H. F.; Vilmer, N.
1996AAS...188.7016D Altcode: 1996BAAS...28..941D
HESSI will investigate the physics of particle acceleration and energy
release in solar flares through an unprecedented combination of high
resolution imaging and spectroscopy of X-rays and gamma rays from 2
keV to 20 MeV during the next solar maximum. It uses Fourier-transform
imaging with 12 bi-grid modulation collimators and cooled germanium and
silicon detectors mounted on a Sun-pointed spin-stabilized spacecraft in
a low-altitude equatorial orbit. HESSI will carry out the first imaging
spectroscopy in hard X-rays with 2 arcseconds angular resolution, time
resolution to tens of ms, and ~ 1 keV energy resolution; the first
gamma-ray line spectroscopy from a spacecraft with ~ 1 keV energy
resolution; and the first gamma-ray line and continuum imaging with
20 arcseconds angular resolution.
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Title: Solar Flares Research During MAX'91 with the High Energy
Imaging Device (HEIDI)
Authors: Orwig, L. E.; Crannell, C. J.; Dennis, B. R.; Starr, R.;
Lang, F. L.; Hurford, G. J.; Prince, T. A.; van Beek, H. F.; Greene,
M. E.; Johnson, W. N.; Norris, J. P.; Wood, K. S.
1990BAAS...22..792O Altcode:
No abstract at ADS
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Title: Book reviews
Authors: Hovenier, J. W.; Ne'Eman, Yuval; Kleczek, J.; Vn Nes, P.;
Somogyi, A. J.; Mewe, R.; Klos, Z.; Bertaux, J. L.; van Beek, H. F.;
't Hooft, G.
1989SSRv...51..229H Altcode:
No abstract at ADS
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Title: Book-Review - Visions of Tomorrow - a Focus on National Space
Transportation Issues
Authors: Soffen, G. A.; van Beek, H. F.
1989SSRv...51..234S Altcode:
No abstract at ADS
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Title: Book-Review - Engineering and Configurations of Space Stations
and Platforms
Authors: van Beek, H. F.
1986SSRv...44..185V Altcode:
No abstract at ADS
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Title: Book reviews
Authors: Gurtovenko, E. A.; Kostik, R. I.; Tlamicha, A.; Zerull, R.;
Schadee, Aert; Mészáros, A.; Néeman, Y.; Giese, R. H.; Sinclair,
A. T.; Kleczek, J.; Trendelenburg, E. A.; Hillebrandt, Wolfgang;
Sehnal, L.; de Graaff, W.; Slottje, C.; Courvisier, T.; van Beek,
H. F.; Baud, B.; de Jager, C.; Danby, J. M. A.; Somov, B. V.;
Cassinelli, J.; Verbunt, F.
1986SSRv...44..177G Altcode:
No abstract at ADS
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Title: Book reviews
Authors: Kleczek, J.; van Gent, R. H.; Rutten, Robert J.; de Munck,
J. C.; Slottje, C.; Severne, G.; Pecker, Jean-Claude; Postma, H.;
Grishchuk, L. P.; Niewenhuijzen, H.; Schuiling, R. D.; van Beek, H. F.;
Reijnen, G. C. M.; Heidmann, Jean; Lemaire, J.; Bleeker, Johan; Icke,
V.; Neéman, Y.; Feast, M. W.; de Graaff, W.
1986SSRv...43..383K Altcode:
No abstract at ADS
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Title: Book-Review - Guidance and Control - 1985
Authors: Culp, R. D.; van Beek, H. F.
1986SSRv...43..389C Altcode:
No abstract at ADS
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Title: Coronal interconnection of two active regions observed in
3.5 8.0 keV X-rays
Authors: Farnik, F.; van Beek, H. F.; Svestka, Z.
1986SoPh..104..321F Altcode:
Using HXIS data, we have studied the further development of the coronal
arch extending towards the SE above active region No. 17255 in November
1980. The arch, studied originally by Švestka (1984) disappeared
on 10 November (after pronounced revival), but since 9 November HXIS
revealed another arch-like structure towards the SW. We have studied
the development of this new structure which appeared to be most likely
an arch interconnecting AR 17255 with AR 17251, located nearly 30° to
the west. This interconnection revived many times during the following
days with intensity varying with the activity in both active regions. We
have estimated the physical characteristics in this coronal structure
and compared them with observations of interconnecting loops made
at lower energies by Skylab in 1973. The temperature (maximum values
7.5-14 × 10<SUP>6</SUP> K) and the density (1.1-5.0 × 10<SUP>9</SUP>
cm<SUP>−3</SUP>) are found to be higher than in the Skylab loops
(a result that could be expected because the HXIS energy range was
harder than that of Skylab) and similar to the values deduced for
the earlier arch system extending to the SE. However, much shorter
decay times of the brightness variations indicate the presence of
conduction in contrast to the SE arch in which conduction was clearly
inhibited. This supports the assumption that the SE and SW coronal
structures were two different phenomena.
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Title: Book-Review - Guidance and Control
Authors: Culp, R. D.; Stafford, P. S.; van Beek, H. F.
1984SSRv...39..379C Altcode:
No abstract at ADS
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Title: Book reviews
Authors: Doom, C.; Schrijver, C. J.; Icke, V.; Rakos, Karl D.; Kleczek,
J.; Forbes, E. G.; Seboldt, W.; Linssen, P. F. J.; McKenna-Lawlor,
S. M. P.; van der Kruit, P. C.; Namba, O.; van Beek, H. F.
1984SSRv...39..375D Altcode:
No abstract at ADS
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Title: Book reviews
Authors: van der Hucht, K. A.; Pedersen, A.; Kesák, Ľ.; Zwaan,
C.; Fárník, F.; Kovalevsky, J.; van Beek, H. F.; Mewe, R.; Page,
D. E.; van Genderen, A. M.; Koch-Miramond, L.; de Jager, C.; Ooms,
G.; Pedersen, Arne; de Jager, C.; Hultqvist, Bengt; Waters, R.;
Schrijver, J.
1984SSRv...38..179V Altcode:
No abstract at ADS
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Title: A position sensitive detector system consisting of an array
of mini-proportional counters.
Authors: van Beek, H. F.; Boelee, A.; van der Laan, J. J. M.; Mels,
W. A.
1984ITNS...31..791V Altcode:
A new position sensitive detector system has been developed for
the Hard X-ray Imaging Spectrometer launched aboard the NASA Solar
Maximum Mission. The instrument operates in the energy range 3.5 - 30
keV. The Xe-gas filled detector system consists of a photon absorption
compartment and an array of 900 mini-proportional counters. The detector
lay-out and the system performance are described.
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Title: Book-Review - Space Manufacturing 1983
Authors: Burke, J. D.; Whitt, A. S.; van Beek, H. F.
1984SSRv...38..183B Altcode:
No abstract at ADS
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Title: Hard X-Ray Studies of the Large Coronal Feature on June
29, 1980
Authors: Harrison, R. A.; Simnett, G. M.; Hoyng, P.; Lafleur, H.;
van Beek, H. F.
1984sii..conf..287H Altcode:
No abstract at ADS
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Title: Grazing incidence Focal Plane Instrument for the wavelength
range 6.5 - 175 nm.
Authors: Werner, W.; van Beek, H. F.
1984SPIE..445..272W Altcode:
The result of a design study on a Focal Plane Instrument for the 6.5
to 175 nm wavelength range is described. The instrument is meant to
be used in combination with a grazing incidence telescope consisting
of a sector out of a full revolution configuration mirror system,
type Wolter II. The presented design is based on the principles of
grazing incidence reflection and conical diffraction. Simultaneously,
radiation from 240 spatial pixels of 1 arcsec × 1 arcsec is analyzed
in four wavelength bands. The spectral resolution varies from 0.003
nm to 0.0075 nm. For detection micro-channel arrays are chosen.
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Title: Book-Review - Low Light Level Detectors in Astronomy
Authors: Eccles, M. J.; Sim, M. E.; Tritton, K. P.; van Beek, H. F.
1984SSRv...38..181E Altcode:
No abstract at ADS
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Title: Book-Review - Developing the Space Frontier
Authors: Naumann, A.; Alexander, G.; van Beek, H. F.
1984SSRv...38..182N Altcode:
No abstract at ADS
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Title: Coronal interconnection of two active regions observed in
3.5-5.5 keV X-rays
Authors: Farnik, F.; van Beek, H. F.
1984AdSpR...4g.243F Altcode: 1984AdSpR...4..243F
Using HXIS data, we have studied further development of the coronal arch
extending towards SE above the active region (AR) No.17255 in November
1980. The disappearance of that arch was followed by the appearance of
another arch-like structure towards SW. We have studied the development
of the new structure and classified it as an arch interconnecting AR
17255 with AR 17251, which was ~30° to the west. We estimate physical
characteristics of this interconnection and compare them with Skylab
data and the earlier arches.
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Title: Evidence for Extensive Magnetic Structures Between Two Active
Regions from Studies of Flares on June 24, 1980
Authors: Simnett, G. M.; Harrison, R. A.; Hoyng, P.; van Beek, H. F.
1984sii..conf..273S Altcode:
No abstract at ADS
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Title: The structure and evolution of a solar flare as observed in
3.5 30 keV X-rays
Authors: Harrison, R. A.; Simnett, G. M.; Hoyng, P.; Lafleur, H.;
van Beek, H. F.
1983SoPh...84..237H Altcode:
On July 5, 1980 the Hard X-Ray Imaging Spectrometer on board the Solar
Maximum Mission observed a complex flare event starting at 22 : 32 UT
from AR 2559 (Hale 16955), then at N 28 W 29, which developed finally
into a 2-ribbon flare. In this paper we compare the X-ray images with
Hα photographs taken at the Big Bear Solar Observatory and identify
the site of the most energetic flare phenomena. During the early
phases of the event the hard X-rays (>16 keV) came from a compact
source located near one of the two bright Hα kernels; we believe the
latter are at the footpoints of a compact magnetic loop. The kernel
identified with the X-ray source is immediately adjacent to one of the
principal sunspots and in fact appears to `rotate' around the sunspot
over 90° in the early phase of the flare. Two intense X-ray bursts
occur at the site of the rotating kernel, and following each burst
the loop fills with hot, X-ray emitting plasma. If the first burst is
interpreted as bremsstrahlung from a beam of electrons impinging on a
collisionally dominated medium, the energy in such electrons, >16
keV, is ∼ 5 × 10<SUP>30</SUP> erg. The altitude of the looptop is
7-10 × 10<SUP>3</SUP> km. The temperature structure of the flare is
extremely non-homogeneous, and the highest temperatures are found in
the top of the loop.
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Title: Observations of a POST Flare Radio Burst in X-Rays
Authors: Svestka, Z.; Hoyng, P.; van Tend, W.; Boelee, A.; de Jager,
C.; Stewart, R. T.; Acton, L. W.; Bruner, E. C.; Gabriel, A. H.;
Rapley, C. G.; de Jager, C.; LaFleur, H.; Nelson, G.; Simnett, G. M.;
van Beek, H. F.; Wagner, W. J.
1982SoPh...75..305S Altcode:
More than six hours after the two-ribbon flare of 21 May 1980, the
hard X-ray spectrometer aboard the SMM imaged an extensive arch above
the flare region which proved to be the lowest part of a stationary
post-flare noise storm recorded at the same time at Culgoora. The X-ray
arch extended over 3 or more arc minutes to a projected distance of
95 000 km, and its real altitude was most probably between 110 000
and 180 000 km. The mean electron density in the cloud was close to
10<SUP>9</SUP> cm<SUP>−3</SUP> and its temperature stayed for many
hours at a fairly constant value of about 6.5 × 10<SUP>6</SUP> K. The
bent crystal spectrometer aboard the SMM confirms that the arch emission
was basically thermal. Variations in brightness and energy spectrum at
one of the supposed footpoints of the arch seem to correlate in time
with radio brightness suggesting that suprathermal particles from
the radio noise regions dumped in variable quantities into the low
corona and transition layer; these particles may have contributed to
the population of the arch, after being trapped and thermalized. The
arch extended along the H<SUB>∥</SUB> = 0 line thus apparently
hindering any upward movement of the upper loops reconnected in the
flare process. There is evidence from Culgoora that this obstacle may
have been present above the flare since 15-30 min after its onset.
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Title: Performance of the hard X-ray imaging spectrometer.
Authors: van Beek, H. F.; Fryer, R. J.
1982JSpRo..19..232V Altcode:
No abstract at ADS
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Title: Optical alignment of an x-ray collimator
Authors: Hoekstra, R.; D'Arnaud, T. E.; van Beek, H. F.
1981ApOpt..20.3630H Altcode:
No abstract at ADS
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Title: Origin and Location of the Hard X-Ray Emission in a Two-Ribbon
Flare
Authors: Hoyng, P.; Duijveman, A.; Machado, M. E.; Rust, D. M.;
Svestka, Z.; Boelee, A.; de Jager, C.; Frost, K. T.; Lafleur, H.;
Simnett, G. M.; van Beek, H. F.; Woodgate, B. E.
1981ApJ...246L.155H Altcode:
No abstract at ADS
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Title: The limb flare of 1980 April 30 as seen by the hard X-ray
imaging spectrometer
Authors: van Beek, H. F.; de Jager, C.; Schadee, A.; Svestka, Z.;
Boelee, A.; Duijveman, A.; Galama, M.; Hoekstra, R.; Hoyng, P.; Fryer,
R.; Simnett, G. M.; Imhof, J. P.; LaFleur, H.; Maseland, H. V. A. M.;
Mels, W. M.; Schrijver, J.; van der Laan, J. J. M.; van Rens, P.; van
Tend, W.; Werkhoven, F.; Willmore, A. P.; Wilson, J. W. G.; Machado,
M. E.; Zandee, W.
1981ApJ...244L.157V Altcode:
X-ray imaging of the limb event of 1980 April 30 shows that the flaring
involved two distinct components: a pointlike component, which was the
source of the initial hard X-ray burst and an extensive tongue reaching
some 30,000 km above the limb. The tongue had a higher temperature
than the other parts of the structure and seemed to be enhanced by
energetic electrons that derived their energy from the initial source.
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Title: Structural development of the X-ray limb flare of 30 April 1980
Authors: de Jager, C.; Hoyng, P.; Lafleur, H.; Schadee, A.; Svestka,
Z.; van Beek, H. F.; van Tend, W.; Fryer, R.; Simnett, G. M.
1981AdSpR...1m.251D Altcode: 1981AdSpR...1..251D
We describe the development of the limb flare of 30 April 1980, 20:20
UT, as observed by the Hard X-ray Imaging Spectrometer (HXIS) aboard
the Solar Maximum Mission (SMM). It consisted of a short-lived bright
nucleus (FWHM < 10,000 km), just inside the Sun's limb; a longer
lasting tongue, extending to a height of ~ 30,000 km, and a more
complicated feature, approximately situated at the Sun's limb. The
tongue was a pre-existing magnetic structure that started emitting
X-rays only a few seconds after the bright nucleus, and which had a
slightly higher temperature than the nucleus; its X-ray emission may
be caused by electrons escaped from the nucleus.
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Title: Solar maximum mission experiment: Early results of the hard
X-ray imaging experiment
Authors: Boelee, A.; de Jager, C.; Duijveman, A.; Galama, M.; Hoekstra,
R.; Hoyng, P.; Imhof, J. P.; Lafleur, H.; Maseland, H. V. A. M.; Mels,
W. A.; Schadee, A.; Schrijver, J.; Svestka, Z.; van Beek, H. F.;
van Rens, P.; van der Laan, J. J. M.; van Tend, W.; Werkhoven, F.;
Wiersma, G.; Zandee, W.; Simnett, G. M.; Charlton, C. P.; Fryer, R.;
Willmore, A. P.; Wilson, J. W. G.; Machado, M. E.
1981AdSpR...1m.255B Altcode: 1981AdSpR...1R.255B
We have selected four widely different flares from the early
period of operations of the Hard X-Ray Imaging Spectrometer (HXIS)
on SMM to illustrate the characteristic imaging properties of this
experiment. For the small flare of April 4, 1980, we demonstrate the
instrument's capability for locating a compact source. In the weak,
but extensive, flare of April 6 we show how well the instrument can
display spatial structure, and also the low level of the instrument
background. In the 1B flare of April 7 we are able to locate positions
of the X-ray emission in the soft and hard channels, and estimate
the positional variations of the emission patches. Finally, in the IN
flare of April 10, which produced the strongest hard X-ray burst we
have seen so far, we repeat some of the studies made for the April 7
event, and also demonstrate the capability of the HXIS instrument to
study the development, with high time resolution, of individual 8”
× 8” elements of the flare.
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Title: Structural development of the X-ray limb flare of 30 April
1980.
Authors: de Jager, C.; Fryer, R.; Hoyng, P.; Lafleur, H.; Schadee,
A.; Simnett, G. M.; Svestka, Z.; van Beek, H. F.; van Tend, W.
1981hea..conf..251D Altcode:
No abstract at ADS
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Title: Solar Maximum Mission experiment: early results of the hard
X-ray imaging experiment.
Authors: Simnett, G. M.; Boelee, A.; Charlton, C. P.; de Jager, C.;
Duijveman, A.; Fryer, R.; Galama, M.; Hoekstra, R.; Hoyng, P.; Imhof,
J. P.; Lafleur, H.; Machado, M. E.; Maseland, H. V. A. M.; Mels,
W. A.; Schadee, A.; Schrijver, J.; Svestka, Z.; van Beek, H. F.;
van Rens, P.; van der Laan, J. J. M.; van Tend, W.; Werkhoven, F.;
Wiersma, G.; Willmore, A. P.; Wilson, J. W. G.; Zandee, W.
1981hea..conf..255S Altcode:
No abstract at ADS
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Title: The HXIS instrument aboard the Solar Maximum Mission
Authors: van Beek, H. F.; Schrijver, H.
1980Ruimt..29..225V Altcode:
After a review of the Solar Maximum Mission (SMM) and SMM satellite,
the paper presents a detailed description of the Hard X-ray Imaging
Spectrometer (HXIS) and associated equipment. Attention is given to
the collimator, the detector system, the analog electronics, and the
onboard computer system. The planning of observations is described,
and first results are presented from April 1980.
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Title: The hard X-ray imaging spectrometer (HXIS).
Authors: van Beek, H. F.; Hoyng, P.; Lafleur, B.; Simnett, G. M.
1980SoPh...65...39V Altcode:
The HXIS, a joint instrument of the Space Research Laboratory at
Utrecht, The Netherlands, and the Department of Space Research of
the University of Birmingham, U.K., images the Sun in hard X-rays: Six
energy bands in energy range 3.5-30 keV, spatial resolution 8″ over Ø
2'40″ and 32″ over Ø 6'24″ field of view, and time resolution of
0.5-7 s depending on the mode of operation. By means of a `flare flag'
it alerts all the other SMM instruments when a flare sets in and informs
them about the location of the X-ray emission. The experiment should
yield information about the position, extension and spectrum of the hard
X-ray bursts in flares, their relation to the magnetic field structure
and to the quasi-thermal soft X-rays, and about the characteristics
and development of `type IV' electron clouds above flare regions.
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Title: Solar MeV protons recorded with Experiment S99 on board
ESRO-IV in 1973.
Authors: van Beek, H. F.; van Gils, J. N.; de Graaff, W.; van Hees,
R. M.
1979smpr.book.....V Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Solar Maximum Mission.
Authors: van Beek, H. F.
1978nisa.symp..295V Altcode: 1978nisa.conf..295V
No abstract at ADS
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Title: A Grid Telescope for Imaging Hard X-Rays
Authors: Hudson, H. S.; Hurford, G. J.; Peterson, L. E.; van Beek,
H. F.
1978nisa.symp..297H Altcode: 1978nisa.conf..297H
No abstract at ADS
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Title: A Hard X-Ray Imaging Collimator
Authors: van Beek, H. F.
1976SSI.....2..197V Altcode:
The characteristics of a new type of imaging collimator, operating in
the energy range 3.5-30 keV, are described. The collimator is part
of an instrument (the 'Hard X-ray Imaging Spectrometer') which aims
at the production of pictures in six energy bands and which has been
proposed for the NASA Solar Maximum Mission. The properties of the
collimator are compared with those of other imaging collimator devices
and modulation collimator systems.
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Title: High time resolution analysis of solar hard X-ray flares
observed on board the ESRO TD-1A satellite.
Authors: Hoyng, Peter; Brown, John C.; van Beek, H. Frank
1976SoPh...48..197H Altcode:
The Utrecht solar hard X-ray spectrometer S-100 on board the ESRO TD-1A
satellite covers the energy range above 25 keV with 12 logarithmically
spaced channels. Continuous sun-pointing is combined with high time
resolution: 1.2 s for the four low energy channels (25-90 keV) and
4.8 s for the others. It is emphasized that the instrument design and
calibration yield data virtually free of pile-up and other instrumental
defects.
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Title: Elementary flare bursts.
Authors: van Beek, H. F.; de Feiter, L. D.; de Jager, C.
1976spre.conf..819V Altcode: 1976spre.proc..819V
Two hard X-ray flares observed on 2 and 7 August 1972 with the hard
X-ray detector of the Utrecht Space Research Laboratory aboard ESRO's
TD-1A satellite are examined in detail. It is shown that both flares can
be decomposed completely into a number of individual Elementary Flare
Bursts (EFB's) with no residual radiation left. For one and the same
flare all EFB's seem to have approximately the same time profile but
these profiles are different for the two flares investigated: the full
widths at half maximum (FWHM) of the EFB's are 5 and 15 s respectively.
---------------------------------------------------------
Title: Determination of the height of hard X-ray sources in the
solar atmosphere by measurement of photospheric albedo photons.
Authors: Brown, J. C.; van Beek, H. F.; McClymont, A. N.
1975A&A....41..395B Altcode:
The importance and difficulties of determining the altitude of hard
X-ray sources in the solar atmosphere are discussed. It is argued that
the only unambiguous means of making this measurement is by utilizing
the photospherically scattered component of the radiation. Specifically,
it is proposed that this can be done by measurement of the angular
distribution of the large patch of photospheric albedo X-rays which is
shown to accompany bright point primary X-ray sources. Quantitative
predictions are made of the brightness distribution of this albedo
'image' and the practical feasibility of observing it is demonstrated in
terms of the hard X-ray imaging spectrometer currently under development
at the Space Research Laboratory in Utrecht.
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Title: Hard X-rays from the sun.
Authors: van Beek, H. F.; Hoyng, P.; de Jager, C.; Stevens, G. A.
1975NTNA...41..101V Altcode:
No abstract at ADS
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Title: Determination of the Height of Hard X-Ray Sources in the
Solar Atmosphere by Measurement of Photospheric Albedo Photons
Authors: Brown, J. C.; van Beek, H. F.
1975IAUS...68..239B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: High Time Resolution Analysis of Solar Flares Observed on
the ESRO Td-Ia Satellite
Authors: Hoyng, P.; Brown, J. C.; Stevens, G.; van Beek, H. F.
1975IAUS...68..233H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: High time resolution analysis of solar flares observed on
the ESRO TD-1A satellite.
Authors: Hoyng, P.; Brown, J. C.; Stevens, G.; van Beek, H. F.
1975IAUS...68Q.233H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: High time resolution analysis of solar flares observed on
the ESRO TD-1A satellite.
Authors: Hoyng, P.; Brown, J. C.; Stevens, G.; van Beek, H. F.
1975IAUS...68R.233H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Determination of the height of hard X-ray sources in the
solar atmosphere by measurement of photospheric albedo photons.
Authors: Brown, J. C.; van Beek, H. F.
1975IAUS...68R.239B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Determination of the height of hard X-ray sources in the
solar atmosphere by measurement of photospheric albedo photons.
Authors: Brown, J. C.; van Beek, H. F.
1975IAUS...68Q.239B Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Time Profiles and Photon Spectra of Solar Hard X-rays
Authors: van Beek, H. F.; de Feiter, L. D.; de Jager, C.
1974ASSL...42..533V Altcode: 1974cimo.symp..533V
With a spectrometer aboard the ESRO TD-1A satellite, time profiles
and photon spectra of solar X-rays have been observed in the energy
range above 24 keV. Most of the X-ray bursts studied thus far appear
to consist of numerous short-lived spikes with rise and decay times of
a few seconds. Such spikes, called 'Elementary Flare Bursts' (EFB's)
cluster together in large numbers and constitute the conventional
high energy flare. The form of the photon spectra could be determined
very accurately and was in all cases of the power-law type. For the
Aug. 4, 1972 flare, the photon spectra appear to be combinations of two
power-law spectra; for the lower energies the spectral coefficient is
smaller than for the higher energies. The transition energy is about
60 keV.
---------------------------------------------------------
Title: Hard X-ray observations of elementary flare bursts, and
their interpretation.
Authors: van Beek, H. F.; de Feiter, L. D.; de Jager, C.
1974spre.conf..447V Altcode: 1974spre.meet..447V
Recent observations of solar hard X-ray bursts, performed with high
time resolution aboard the ESRO TD-1A satellite, show that often these
bursts consist of numerous short-lived spikes with rise and decay times
of the order of a few seconds. It is argued that these spikes, which
are called elementary flare bursts (EFB), are the essential physical
phenomena, which, clustered together in large numbers, constitute the
conventional high-energy flare. For some cases studied it is found that
the rise and decay times can be as low as 1 to 2 seconds; individual
points deviate only slightly from this average value. These times do
not depend on the photon energy; this seems to indicate that the EFBs
occur at a fairly low level in the chromosphere (less than or equal to
1500 km above the photosphere). For one particular case studied this
conclusion is corroborated by the observation of short-lived flashes
as observed optically with an interference filter centered at 3835
A. In this region a considerable part of the ambient electrons are
accelerated to energies of several tens of kiloelectron volts.
---------------------------------------------------------
Title: First results of the solar hard X-ray spectrometer on board
the ESRO TD-1A satellite.
Authors: van Beek, H. F.; de Feiter, L. D.
1973spre.conf..777V Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Development and performance of a solar hard x-ray spectrometer
Authors: van Beek, H. F. Frank
1973PhDT........38V Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Hard Solar X-Ray Spectrometer on Board the ESRO Td-1
a Satellite
Authors: van Beek, H. F.; de Feiter, L. D.
1973sari.conf..103V Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Electron-ion and ion-ion reaction rate coefficients at low
altitudes during a PCA event.
Authors: Larsen, T. R.; Jespersen, M.; Murdin, J.; Bowling, T. S.;
van Beek, H. F.; Stevens, G. A.
1972JATP...34..787L Altcode:
Based on experimental data from several ESRO PCA rocket flights
some considerations are presented regarding the mean values
of the electron-ion dissociative recombination coefficient (
α<SUB>d</SUB>) and the ion-ion neutralization coefficient (
α<SUB>i</SUB>). The estimates yield values for α<SUB>d</SUB> =
10 <SUP>-5</SUP>cm<SUP>3</SUP>sec<SUP>-1</SUP> for heights between
60 and 67 km. The data indicate that α<SUP>i</SUP> is smaller than
α<SUB>d</SUB> by a factor of 100.
---------------------------------------------------------
Title: De suksesvolle lancering van ESRO's Thor-Delta 1A satelliet.
Authors: van Beek, H. F.; de Jager, C.; Lamers, H.
1972HemD...70..171V Altcode:
No abstract at ADS
---------------------------------------------------------
Title: An Automatic Stabilized Detection System for Measuring Soft
Celestial X-Rays
Authors: den Boggende, A. J. F.; van Beek, H. F.; Brinkman, A. C.;
Lafleur, H. Th. J. A.
1971IAUS...41..211D Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Rocket observations of protons and alpha particles at Andøya
after the solar flares of 24 and 25 February 1969.
Authors: van Beek, H. F.; van Gils, J. N.
1970spre.conf..831V Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Rocket Observations of Protons and α-Particles at Andøya
after the Solar Flares of 24th-25th February 1969
Authors: van Beek, H. F.; Stevens, G. A.
1970ASSL...19..508V Altcode: 1970iso..conf..508V
No abstract at ADS
---------------------------------------------------------
Title: A measurement of auroral electrons in the 1-10 MeV range
Authors: Van Gils, J. N.; Van Beek, H. F.; De Fetter, L. D.; Hendrickx,
R. V.
1969P&SS...17..255V Altcode:
Particle fluxes have been measured by means of shielded Geiger-Müller
telescopes mounted m a rocket, which was launched from ESRANGE(Kiruna)
into a diffuse aurora. The analysis of the dependence of the counting
rates on altitude indicates that a weak flux of energetic electrons,
1-10 MeV, has been detected.
