The GEM scintillation in He–CF4, Ar–CF4, Ar–TEA and Xe–TEA mixtures

Fraga, M.M.F.R.; Fraga, F.A.F.; Fetal, S.T.G.; Margato, L.M.S.; Ferreira‐Marques, R.; Policarpo, A.

doi:10.1016/s0168-9002(03)00758-7

Cited by 71 publications

(57 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In figure 10, the quenching of the Ar lines for a CF 4 concentration increase from 4 to 20% is higher than the quenching of the same lines reported in figure 2 of Fraga et al (2003), where the CF 4 concentration increased from 5 to 67%. This effect could be caused by the presence of some air inside the scintillating GEM detector chamber, which acts as a quencher reducing the Ar emission.…”

Section: Emission Spectramentioning

confidence: 58%

“…For more details, see references within that article. The Ar/CF 4 emission spectrum also has a band in the UV region (Fraga et al 2003), but this spectral region was not of interest for this work since the QE of the Kodak KAF-0401E CCD is zero in the UV range. In fact, the QE of the CCD matches quite well the Ar/CF 4 emission spectrum: the QE has a maximum of about 62% at ∼640 nm, the wavelength for which Ar/CF 4 also has a maximum (figure 5).…”

Section: The Ar/cf 4 Emission Spectrummentioning

confidence: 99%

See 1 more Smart Citation

Characterization of a scintillating GEM detector with low energy x-rays

Seravalli¹,

Boer²,

Geurink³

et al. 2008

Phys. Med. Biol.

View full text Add to dashboard Cite

A two-dimensional position-sensitive dosimetry system based on a scintillating gas detector is being developed with the aim of using it for pre-treatment verification of dose distributions in charged particle therapy. The dosimetry system consists of a chamber filled with an Ar/CF 4 scintillating gas mixture, inside which two cascaded gas electron multipliers (GEMs) are mounted. A GEM is a thin kapton foil with copper cladding structured with a regular pattern of sub-mm holes. In such a system, light quanta are emitted by the scintillating gas mixture during the electron avalanches in the GEM holes when radiation traverses the detector. The light intensity distribution is proportional to the energy deposited in the detector's sensitive volume by the beam. In the present work, we investigated the optimization of the scintillating GEM detector light yield. The light quanta are detected by means of a CCD camera or a photomultiplier tube coupled to a monochromator. The GEM charge signal is measured simultaneously. We have found that with 60 μm diameter double conical GEM holes, a brighter light signal and a higher electric signal are obtained than with 80 μm diameter holes. With an Ar + 8% CF 4 volume concentration, the highest voltage across the GEMs and the largest light and electric signals were reached. Moreover, we have found that the emission spectrum of Ar/CF 4 is independent of (1) the voltages applied across the GEMs, (2) the x-ray beam intensity and (3) the GEM hole diameter. On the other hand, the ratio of Ar to CF 4 peaks in the spectrum changes when the concentration of the latter gas is varied.

show abstract

Section: Emission Spectramentioning

confidence: 58%

Section: The Ar/cf 4 Emission Spectrummentioning

confidence: 99%

Characterization of a scintillating GEM detector with low energy x-rays

Seravalli¹,

Boer²,

Geurink³

et al. 2008

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…Optical readout of the light produced by GEM based detectors was already studied in the past ( [8], [9]) and showed several advantages:…”

Section: Reading the Light: A Change Of Paradigmmentioning

confidence: 99%

CYGNUS: development of a high resolution TPC for rare events

Pinci¹,

Renga²,

Voena³

et al. 2017

Proceedings of the European Physical Society Conference on High Energy Physics — PoS(EPS-HEP2017)

View full text Add to dashboard Cite

The R&D of a gas detector prototype for high precision tracking of low energy nuclear recoils over large volume is presented in this paper. The scintillation light accompanying the electronic avalanches in a triple GEM structure is detected by a CMOS-based camera. The sensor provides very high granularity along with a very low noise and high sensitivity. Space resolution of the order of tens of µm were measured on the GEM plane (xy). The Negative Ion Drift method to reconstruct the depth of track within the sensitive volume was studied. Recent tests on beam demonstrated the feasibility of the NID method with a small amount of SF 6 even at nearly ambient pressure. The use of a concurrent light readout by means of a suitable photomultiplier provides the necessary timing informations. A time resolution of the order of 5 ns was measured.

show abstract

“…High density of Fluorine atoms makes the media sensitive to spin-dependent interactions [4]. Furthermore, CF 4 was reported as a good scintillator in the far UV [5], as well as in the UV and visible wavelength regions exhibiting fast scintillation and high photon yields [6][7][8]. These properties make CF 4 an attractive detection media in detectors with optical readout such as 2D position sensitive thermal neutron detectors [9] and TPCs for different purposes (e.g.…”

Section: Introductionmentioning

confidence: 99%