87 research outputs found
A position- and time-sensitive photon-counting detector with delay-line read-out
We have developed image intensifier tubes with delay-anode read-out for time-
and position-sensitive photon counting. The timing precision is better than 1
ns with 1000x1000 pixels position resolution and up to one megacounts/s
processing rate. Large format detectors of 40 and 75 mm active diameter with
internal helical-wire delay-line anodes have been produced and specified. A
different type of 40 and 25 mm tubes with semi-conducting screen for image
charge read-out allow for an economic and robust tube design and for placing
the read-out anodes outside the sealed housing. Two types of external
delay-line anodes, i.e. pick-up electrodes for the image charge, have been
tested. We present tests of the detector and anode performance. Due to the low
background this technique is well suited for applications with very low light
intensity and especially if a precise time tagging for each photon is required.
As an example we present the application of scintillator read-out in
time-of-flight (TOF) neutron radiography. Further applications so far are
Fluorescence Life-time Microscopy (FLIM) and AstronomyComment: Proceedings of SPIE Conference "Optics and Optoelectronics", 16 - 19.
Apr.200
High Spatial Resolution Fast-Neutron Imaging Detectors for Pulsed Fast-Neutron Transmission Spectroscopy
Two generations of a novel detector for high-resolution transmission imaging
and spectrometry of fast-neutrons are presented. These devices are based on a
hydrogenous fiber scintillator screen and single- or multiple-gated intensified
camera systems (ICCD). This detector is designed for energy-selective neutron
radiography with nanosecond-pulsed broad-energy (1 - 10 MeV) neutron beams.
Utilizing the Time-of-Flight (TOF) method, such a detector is capable of
simultaneously capturing several images, each at a different neutron energy
(TOF). In addition, a gamma-ray image can also be simultaneously registered,
allowing combined neutron/gamma inspection of objects. This permits combining
the sensitivity of the fast-neutron resonance method to low-Z elements with
that of gamma radiography to high-Z materials.Comment: Also published in JINST:
http://www.iop.org/EJ/abstract/1748-0221/4/05/P0501
Advances in imaging THGEM-based detectors
The thick GEM (THGEM) [1] is an "expanded" GEM, economically produced in the
PCB industry by simple drilling and etching in G-10 or other insulating
materials (fig. 1). Similar to GEM, its operation is based on electron gas
avalanche multiplication in sub-mm holes, resulting in very high gain and fast
signals. Due to its large hole size, the THGEM is particularly efficient in
transporting the electrons into and from the holes, leading to efficient
single-electron detection and effective cascaded operation. The THGEM provides
true pixilated radiation localization, ns signals, high gain and high rate
capability. For a comprehensive summary of the THGEM properties, the reader is
referred to [2, 3]. In this article we present a summary of our recent study on
THGEM-based imaging, carried out with a 10x10 cm^2 double-THGEM detector.Comment: 3 pages, 3 figures. Presented at the 10th Pisa Meeting on Advanced
Detectors; ELBA-Italy; May 21-27 200
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