-
H. Anderhub,
M. Backes,
A. Biland,
V. Boccone,
I. Braun,
T. Bretz,
J. Buß,
F. Cadoux, V. Commichau,
L. Djambazov, [......],
T. Steinbring,
F. Temme,
J. Thaele,
S. Tobler,
G. Viertel,
P. Vogler,
R. Walter,
K. Warda,
Q. Weitzel,
M. Z"anglein
[show abstract]
[hide abstract]
ABSTRACT: The First G-APD Cherenkov Telescope (FACT) is designed to detect cosmic
gamma-rays with energies from several hundred GeV up to about 10 TeV using the
Imaging Atmospheric Cherenkov Technique. In contrast to former or existing
telescopes, the camera of the FACT telescope is comprised of solid-state
Geiger-mode Avalanche Photodiodes (G-APD) instead of photomultiplier tubes for
photo detection. It is the first full-scale device of its kind employing this
new technology. The telescope is operated at the Observatorio del Roque de los
Muchachos (La Palma, Canary Islands, Spain) since fall 2011. This paper
describes in detail the design, construction and operation of the system,
including hardware and software aspects. Technical experiences gained after one
year of operation are discussed and conclusions with regard to future projects
are drawn.
04/2013;
-
H Anderhub,
M Backes,
A Biland,
A Boller,
I Braun,
T Bretz, V Commichau,
L Djambazov,
D Dorner,
C Farnier, [......],
R Rohlfs,
U Röser,
J -P Stucki,
J Thaele,
O Tibolla,
G Viertel,
P Vogler,
R Walter,
K Warda,
Q Weitzel
[show abstract]
[hide abstract]
ABSTRACT: Within the FACT project, we construct a new type of camera based on Geiger-mode avalanche photodiodes (G-APDs). Compared to photomultipliers, G-APDs are more robust, need a lower operation voltage and have the potential of higher photon-detection efficiency and lower cost, but were never fully tested in the harsh environments of Cherenkov telescopes. The FACT camera consists of 1440 G-APD pixels and readout channels, based on the DRS4 (Domino Ring Sampler) analog pipeline chip and commercial Ethernet components. Preamplifiers, trigger system, digitization, slow control and power converters are integrated into the camera.
Journal of Instrumentation 01/2012; 7(01):C01073. · 1.87 Impact Factor
-
M. Aguilar,
J. Alcaraz,
J. Allaby,
B. Alpat,
G. Ambrosi,
H. Anderhub,
L. Ao,
A. Arefiev,
L. Arruda,
P. Azzarello, [......],
Z. P. Zhang,
D. X. Zhao,
F. Zhou,
Y. Zhou,
G. Y. Zhu,
W. Z. Zhu,
H. L. Zhuang,
A. Zichichi,
B. Zimmermann,
and P. Zuccon
[show abstract]
[hide abstract]
ABSTRACT: The variety of isotopes in cosmic rays allows us to study different aspects of the processes that cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere. In this paper, we present measurements of the isotopic ratios 2H/4He, 3He/4He, 6Li/7Li, 7Be/(9Be+10Be), and 10B/11B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The measurements are based on the data collected by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight in 1998 June.
The Astrophysical Journal 07/2011; 736(2):105. · 6.02 Impact Factor
-
M. Aguilar,
J. Alcaraz,
J. Allaby,
B. Alpat,
G. Ambrosi,
H. Anderhub,
L. Ao,
A. Arefiev,
L. Arruda,
P. Azzarello, [......],
Z. P. Zhang,
D. X. Zhao,
F. Zhou,
Y. Zhou,
G. Y. Zhu,
W. Z. Zhu,
H. L. Zhuang,
A. Zichichi,
B. Zimmermann,
and P. Zuccon
[show abstract]
[hide abstract]
ABSTRACT: Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended sets of ratios can provide stronger constraints on the propagation models. In this paper, the relative abundances of light-nuclei lithium, beryllium, boron, and carbon are presented. The secondary-to-primary ratios Li/C, Be/C, and B/C have been measured in the kinetic energy range 0.35-45 GeV nucleon–1. The isotopic ratio 7Li/6Li is also determined in the magnetic rigidity interval 2.5-6.3 GV. The secondary-to-secondary ratios Li/Be, Li/B, and Be/B are also reported. These measurements are based on the data collected by the Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle flight in 1998 June. Our experimental results are in substantial agreement with other measurements, where they exist. We describe our light-nuclei data with a diffusive-reacceleration model. A 10%-15% overproduction of Be is found in the model predictions and can be attributed to uncertainties in the production cross-section data.
The Astrophysical Journal 11/2010; 724(1):329. · 6.02 Impact Factor
-
H Anderhub,
M. Backes,
A Biland,
A. Boller,
I. Braun,
T. Bretz,
S. Commichau, V Commichau,
M. Domke,
D. Dorner, [......],
M. Rissi,
M. Ribordy,
U Röser,
L. S. Stark,
J. -P. Stucki,
O. Tibolla,
G. Viertel,
P. Vogler,
K. Warda,
Q. Weitzel
[show abstract]
[hide abstract]
ABSTRACT: Geiger-mode Avalanche Photodiodes~(G-APD) bear the potential to significantly improve the sensitivity of Imaging Air Cherenkov Telescopes (IACT). We are currently building the First G-APD Cherenkov Telescope (FACT) by refurbishing an old IACT with a mirror area of 9.5 square meters and construct a new, fine pixelized camera using novel G-APDs. The main goal is to evaluate the performance of a complete system by observing very high energy gamma-rays from the Crab Nebula. This is an important field test to check the feasibility of G-APD-based cameras to replace at some time the PMT-based cameras of planned future IACTs like AGIS and CTA. In this article, we present the basic design of such a camera as well as some important details to be taken into account. Comment: Poster shown at HEAD 2010, Big Island, Hawaii, March 1-4, 2010
10/2010;
-
H Anderhub,
M. Backes,
A Biland,
A. Boller,
I. Braun,
T. Bretz,
S. Commichau, V Commichau,
D. Dorner,
A. Gendotti, [......],
D Renker,
W. Rhode,
M. Rissi,
U Röser,
S. Rollke,
L. S. Stark,
J. -P. Stucki,
G. Viertel,
P. Vogler,
Q. Weitzel
[show abstract]
[hide abstract]
ABSTRACT: Geiger-mode avalanche photodiodes (G-APD) are promising new sensors for light detection in atmospheric Cherenkov telescopes. In this paper, the design and commissioning of a 36-pixel G-APD prototype camera is presented. The data acquisition is based on the Domino Ring Sampling (DRS2) chip. A sub-nanosecond time resolution has been achieved. Cosmic-ray induced air showers have been recorded using an imaging mirror setup, in a self-triggered mode. This is the first time that such measurements have been carried out with a complete G-APD camera. Comment: 9 pages with 11 figures
11/2009;
-
M Aguilar,
J Alcaraz,
J Allaby,
B Alpat,
G Ambrosi,
H Anderhub,
L Ao,
A Arefiev,
P Azzarello,
E Babucci, [......],
Z Z Xu,
H Y Zhang,
Z P Zhang,
D X Zhao,
G Y Zhu,
W Z Zhu,
H L Zhuang,
A Zichichi,
B Zimmermann,
P Zuccon
[show abstract]
[hide abstract]
ABSTRACT: The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the ∼100MeV to 1TeV range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected 10 8 cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary π − and μ − emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission.
Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 01/2005; 234:321-332. · 1.21 Impact Factor
-
M. Aguilar,
J Alcaraz,
J. Allaby,
B Alpat,
G Ambrosi,
H Anderhub,
L. Ao,
A. Arefiev,
P. Azzarello,
E Babucci, [......],
Z Z Xu,
H Y Zhang,
Z P Zhang,
D X Zhao,
G Y Zhu,
W. Z. Zhu,
H L Zhuang,
A. Zichichi,
B. Zimmermann,
P. Zuccon
[show abstract]
[hide abstract]
ABSTRACT: The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 (June 1998) in a 51.7° orbit at altitudes between 320 and 390km.
A search for antihelium nuclei in the rigidity range 1-140GV was performed. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of <1.1×1E-6 was obtained.
The high energy proton, electron, positron, helium, antiproton and deuterium spectra were accurately measured.
For each particle and nuclei two distinct spectra were observed: a higher energy spectrum and a substantial second spectrum. Positrons in the second spectrum were found to be much more abundant than electrons. Tracing particles from the second spectra shows that most of them travel for an extended period of time in the geomagnetic field, and that the positive particles (p and e+) and negative ones (e-) originate from two complementary geographic regions. The second helium spectrum flux over the energy range 0.1-1.2GeV/nucleon was measured to be (6.3+/-0.9)×10^-3(m^2ssr)^-1. Over 90 percent of the helium flux was determined to be 3He at the 90% confidence level.
Physics Reports 08/2002; 366(6):331. · 20.39 Impact Factor
-
J Alcaraz,
B Alpat,
G Ambrosi,
H Anderhub,
L. Ao,
A. Arefiev,
P. Azzarello,
E Babucci,
L Baldini,
M Basile, [......],
P Yeh,
Z Z Xu,
H Y Zhang,
Z P Zhang,
D X Zhao,
G Y Zhu,
W. Z. Zhu,
H L Zhuang,
A. Zichichi,
B. Zimmermann
[show abstract]
[hide abstract]
ABSTRACT: The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m(2)) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A "scated-down" version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS. (C) 2002 Elsevier Science B.V. All rights reserved.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 02/2001; 478(1-2):119. · 1.21 Impact Factor
-
J Alcaraz,
B Alpat,
G Ambrosi,
H Anderhub,
L. Ao,
A. Arefiev,
P. Azzarello,
E Babucci,
L Baldini,
M Basile, [......],
P Yeh,
Z Z Xu,
H Y Zhang,
Z P Zhang,
D X Zhao,
G Y Zhu,
W. Z. Zhu,
H L Zhuang,
A. Zichichi,
B. Zimmermann
[show abstract]
[hide abstract]
ABSTRACT: The helium spectrum from 0.1 to /100 GeV/nucleon was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at altitudes near 380 km. Above the geomagnetic cutoff the spectrum is parameterized by a power law. Below the geomagnetic cutoff a second helium spectrum was observed. In the second helium spectra over the energy range 0.1 to /1.2 GeV/nucleon the flux was measured to be (6.3+/-0.9)×10-3(m2 secsr)-1 and more than ninety percent of the helium was determined to be 3He (at the 90% CL). Tracing helium from the second spectrum shows that about half of the 3He travel for an extended period of time in the geomagnetic field and that they originate from restricted geographic regions similar to protons and positrons.
Physics Letters B 10/2000; 494(3-4):193. · 3.95 Impact Factor
-
J Alcaraz,
B Alpat,
G Ambrosi,
H Anderhub,
L. Ao,
A. Arefiev,
P. Azzarello,
E Babucci,
L Baldini,
M Basile, [......],
P Yeh,
Z Z Xu,
H Y Zhang,
Z P Zhang,
D X Zhao,
G Y Zhu,
W. Z. Zhu,
H L Zhuang,
A. Zichichi,
B. Zimmermann
[show abstract]
[hide abstract]
ABSTRACT: The primary proton spectrum in the kinetic energy range 0.2 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS–91 at an altitude of 380 km. The complete data set combining three shuttle attitudes and including all known systematic effects is presented.
Physics Letters B 09/2000; 490:27. · 3.95 Impact Factor
-
J Alcaraz,
B Alpat,
G Ambrosi,
H Anderhub,
L. Ao,
A. Arefiev,
P. Azzarello,
E Babucci,
L Baldini,
M Basile, [......],
P Yeh,
Z Z Xu,
H Y Zhang,
Z P Zhang,
D X Zhao,
G Y Zhu,
W. Z. Zhu,
H L Zhuang,
A. Zichichi,
B. Zimmermann
[show abstract]
[hide abstract]
ABSTRACT: The lepton spectra in the kinetic energy ranges 0.2 to 40 GeV for e− and 0.2 to 3 GeV for e+ were measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS–91 at altitudes near 380 km. From the origin of the leptons two distinct spectra were observed: a higher energy spectrum and a substantial second spectrum with positrons much more abundant than electrons. Tracing leptons from the second spectra shows that most of these leptons travel for an extended period of time in the geomagnetic field and that the e+ and e− originate from two complementary geographic regions.
Physics Letters B 06/2000; 484(1-2):10. · 3.95 Impact Factor
-
J. Alcaraz,
B. Alpat,
G. Ambrosi,
H. Anderhub,
L. Ao,
A. Arefiev,
P. Azzarello,
E. Babucci,
L. Baldini,
M. Basile, [......],
P. Yeh,
Z.Z. Xu,
H.Y. Zhang,
Z.P. Zhang,
D.X. Zhao,
G.Y. Zhu,
W.Z. Zhu,
H.L. Zhuang,
A. Zichichi,
B. Zimmermann
[show abstract]
[hide abstract]
ABSTRACT: The lepton spectra in the kinetic energy ranges 0.2 to 40 GeV for e− and 0.2 to 3 GeV for e+ were measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS–91 at altitudes near 380 km. From the origin of the leptons two distinct spectra were observed: a higher energy spectrum and a substantial second spectrum with positrons much more abundant than electrons. Tracing leptons from the second spectra shows that most of these leptons travel for an extended period of time in the geomagnetic field and that the e+ and e− originate from two complementary geographic regions.
Physics Letters B. 06/2000; 484(1-2):10-22.
-
J. Alcaraz,
D. Alvisi,
B. Alpat,
G. Ambrosi,
H. Anderhub,
L. Ao,
A. Arefiev,
P. Azzarello,
E. Babucci,
L. Baldini, [......],
S.W. Ye,
P. Yeh,
Z.Z. Xu,
H.Y. Zhang,
Z.P. Zhang,
D.X. Zhao,
G.Y. Zhu,
W.Z. Zhu,
H.L. Zhuang,
A. Zichichi
[show abstract]
[hide abstract]
ABSTRACT: The proton spectrum in the kinetic energy range 0.1 to 200 GeV was measured by the Alpha Magnetic Spectrometer (AMS) during space shuttle flight STS-91 at an altitude of 380 km. Above the geomagnetic cutoff the observed spectrum is parameterized by a power law. Below the geomagnetic cutoff a substantial second spectrum was observed concentrated at equatorial latitudes with a flux ∼70 m−2 s−1 sr−1. Most of these second spectrum protons follow a complicated trajectory and originate from a restricted geographic region.
Physics Letters B 01/2000; 472(1-2):215-226. · 3.95 Impact Factor
-
J. Alcaraz,
D. Alvisi,
B. Alpat,
G. Ambrosi,
H. Anderhub,
L. Ao,
A. Arefiev,
P. Azzarello,
E. Babucci,
L. Baldini, [......],
L.G. Yan,
C.G. Yang,
M. Yang,
P. Yeh,
H.Y. Zhang,
D.X. Zhao,
G.Y. Zhu,
W.Z. Zhu,
H.L. Zhuang,
A. Zichichi
[show abstract]
[hide abstract]
ABSTRACT: The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 in a 51.7° orbit at altitudes between 320 and 390 km. A total of 2.86×106 helium nuclei were observed in the rigidity range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of <1.1×10−6 is obtained.
Physics Letters B 09/1999; 461(4):387-396. · 3.95 Impact Factor
-
Collaboration,
M. Acciarri,
O. Adriani,
M. Aguilar-Benitez,
S. Ahlen,
J. Alcaraz,
G. Alemanni,
J. Allaby,
A. Aloisio,
G. Alverson, [......],
P. Zemp,
Y. Zeng,
Z. Zhang,
Z. P. Zhang,
B. Zhou,
Y. Zhou,
G. Y. Zhu,
R. Y. Zhu,
A. Zichichi,
F. Ziegler
Physics Letters B 04/1998; 427:409-412. · 3.95 Impact Factor
-
Collaboration,
M. Acciarri,
O. Adriani,
M. Aguilar-Benitez,
S. Ahlen,
J. Alcaraz,
G. Alemanni,
J. Allaby,
A. Aloisio,
G. Alverson, [......],
Yu. Zalite,
P. Zemp,
Y. Zeng,
Z. Zhang,
Z. P. Zhang,
B. Zhou,
G. Y. Zhu,
R. Y. Zhu,
A. Zichichi,
F. Ziegler
[show abstract]
[hide abstract]
ABSTRACT: We report on measurements of mass and total decay width of the W boson
and of triple-gauge-boson couplings, γWW and ZWW, with the L3
detector at LEP. W-pair events produced in e+e-
interactions between 161GeV and 172GeV centre-of-mass energy are
selected in a data sample corresponding to a total luminosity of 21.2
pb-1. The mass and total decay width of the W boson are
determined to be MW=80.75+0.26-0.27
(exp.)+/-0.03 (LEP) GeV and
ΓW=1.74+0.88-0.78 (stat.)+/-0.25
(syst.) GeV, respectively. Limits on anomalous triple-gauge-boson
couplings, γWW and ZWW, are determined, in particular
-1.5<δZ<1.9 (95% CL), excluding vanishing ZWW
coupling at more than 95% confidence level.
Physics Letters B 10/1997; 413:176-190. · 3.95 Impact Factor
-
S Bachmann,
F. Beiel,
C Camps, V Commichau,
G Flugge,
K Hangarter,
J. Kremp,
D. Macke,
M. Petertill,
O Pooth,
P Schmitz,
R Schulte,
H. Szczesny,
M Tonutti
[show abstract]
[hide abstract]
ABSTRACT: A banana shaped closed design MSGC detector module was tested together with silicon detectors and other MSGCs in a 100 GeV muon beam. Despite of an undesirable geometry of the test setup, a spatial resolution below 40 m was reached. The efficiency of the module, defined by track reconstruction, showed to be 95.6%. 1 Setup A prototype module for the forward tracker of CMS, built in the Aachen closed design, was tested in a 100 GeV --Beam in CERN's X5 area. The substrates had aluminium artwork 1) on D263 glass 2) with a pitch varying from 180 m to 200 m over a length of 120 mm. For details concerning the construction and overall performance see [1]. Additionally, two silicon detectors 3) as well as four other MSGCs 4) were in the beam. For this analysis the following detectors were used: ffl single-sided silicon detector, 128 horizontal strips with 50 m pitch, ffl one half of a double-sided silicon detector, 128 vertical strips with 100 m pitch, ffl one of the MSGCs, 384 ho...
10/1997;
-
Collaboration,
M. Acciarri,
O. Adriani,
M. Aguilar-Benitez,
S. Ahlen,
J. Alcaraz,
G. Alemanni,
J. Allaby,
A. Aloisio,
G. Alverson, [......],
Yu. Zalite,
P. Zemp,
Y. Zeng,
Z. Zhang,
Z. P. Zhang,
B. Zhou,
G. Y. Zhu,
R. Y. Zhu,
A. Zichichi,
F. Ziegler
[show abstract]
[hide abstract]
ABSTRACT: A search for the Standard Model Higgs boson has been performed with the
L3 detector at LEP. The data sample was collected at three
centre-of-mass energies, 161.3, 170.3 and 172.3GeV with integrated
luminosities of 10.8, 1.0 and 9.2 pb, respectively. No Higgs signal is
observed. In combination with previous data taken at the Z resonance, a
lower Higgs mass limit, MH>69.5GeV, is obtained at 95%
confidence level.
Physics Letters B 09/1997; 411:373-386. · 3.95 Impact Factor
-
S Bachmann,
F. Beiel,
C Camps, V Commichau,
G Flugge,
K Hangarter,
J. Kremp,
D. Macke,
M. Petertill,
O Pooth,
P Schmitz,
R Schulte,
H. Szczesny,
M Tonutti
[show abstract]
[hide abstract]
ABSTRACT: For the application of MSGCs at CMS it is of special importance to optimize the time resolution of these detectors which is determined by the signal developement in the detector and its processing by the front-end electronics. In this paper we study the timing properties of MSGCs operated in combination with the PreMux128 front-end chip, performing double correlated sampling. The results are compared to calculations from a simulation program. Using this program the method of the weighted sum --- an alternative sampling scheme to double correlated sampling --- is investigated and optimized. 1 Introduction The inner tracking system of the Compact Myon Solenoid (CMS) detector [1] is divided in the innermost part consisting of silicon pixel detectors, surrounded by 50 m pitch silicon strip detectors and Microstrip Gas Chambers (MSGCs) of 200 m pitch (see figure 1). This high granularity system yields low occupancy necessary for pattern pitch: cathode 70 m 2.9 mm 0.1 mm glass driftplan...
09/1997;
