Speaker
Description
Detectors based on Chemical Vapor Deposition (CVD) diamond have been used
extensively and successfully in beam conditions/beam loss monitors as the
innermost detectors in the highest radiation areas of Large Hadron Collider
(LHC) experiments. For future experiments at CERN it is expected that
the innermost detectors will accumulate an order of magnitude larger
fluence than present experiments. This trend of increasing required
radiation tolerance is now common in areas where sources and beams are
developed with higher energy or higher intensity to reach new regimes
of physics. As a result an enormous effort is ongoing to find detector
materials that operate after fluences of >10^{16} particles/cm^2.
Diamond is one candidate for such a material primarily due to its large
displacement energy which enhances its inherent radiation tolerance.
Over the last two years the RD42 collaboration has constructed a series
of 3D pixel detectors using CVD diamond as the active material and
laser fabricated columns in the bulk and characterized them in test beams.
This article presents beam test results of 3D pixel detectors fabricated with
poly-crystalline CVD diamonds. The cells of the devices had a size of
50 um x 50 um with columns 2.6 um in diameter. The cells were ganged in a
1 x 5 and 3 x 2 pattern to match the layouts of the pixel read-out
electronics currently used in the ATLAS and CMS experiments at the Large
Hadron Collider, respectively. In beam tests, using tracks reconstructed
with a high precision tracking telescope, a tracking efficiency of 99.3%
was achieved. The efficiency of both devices plateaus at a bias voltage of
30V. In addition to the test beam results, the effects on charge collection
in poly-crystalline CVD 3D diamond pixel devices due to radiation will
be discussed leading to methods for achieving a device capable of operating
at 10^{17} particles/cm^2 .
| Submission declaration | Original and unpublished |
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