ATLAS diamond Beam Condition Monitor Gorišek, A.; Cindro, V.; Dolenc, I. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2007, Letnik:
572, Številka:
1
Journal Article
Recenzirano
The ATLAS experiment has chosen to use diamond for its Beam Condition Monitor (BCM) given its radiation hardness, low capacitance and short charge collection time. In addition, due to low leakage ...current diamonds do not require cooling. The ATLAS Beam Condition Monitoring system is based on single beam bunch crossing measurements rather than integrating the accumulated particle flux. Its fast electronics will allow separation of LHC collisions from background events such as beam gas interactions or beam accidents. There will be two stations placed symmetrically about the interaction point along the beam axis at
z
=
±
183.8
cm
. Timing of signals from the two stations will provide almost ideal separation of beam–beam interactions and background events. The ATLAS BCM module consists of diamond pad detectors of
1
cm
2
area and
500
μ
m
thickness coupled to a two-stage RF current amplifier. The production of the final detector modules is almost done. A
S
/
N
ratio of 10:1 has been achieved with minimum ionizing particles (MIPs) in the test beam setup at KEK. Results from the test beams and bench measurements are presented.
Beam conditions and the potential detector damage resulting from their anomalies have pushed the LHC experiments to plan their own monitoring devices in addition to those provided by the machine. ...ATLAS decided to build a telescope composed of two stations with four diamond pad detector modules each, placed symmetrically around the interaction point at
z
=
±
183.8
cm
and
r
∼
55
mm
(
η
∼
4.2
). Equipped with fast electronics it allows time-of-flight separation of events resulting from beam anomalies from normally occurring
p–
p interactions. In addition it will provide a coarse measurement of the LHC luminosity in ATLAS. Ten detector modules have been assembled and subjected to tests, from characterization of bare diamonds to source and beam tests. Preliminary results of beam test in the CERN PS indicate a signal-to-noise ratio of
14
±
2
.
A pixel detector with a CVD diamond sensor has been studied in a 180
GeV
/
c
pion beam. The charge collection properties of the diamond sensor were studied as a function of the track position, which ...was measured with a silicon microstrip telescope. Non-uniformities were observed on a length scale comparable to the diamond crystallites' size. In some regions of the sensor, the charge drift appears to have a component parallel to the sensor surface (i.e., normal to the applied electric field) resulting in systematic residuals between the track position and the hits position as large as
40
μ
m
. A numerical simulation of the charge drift in polycrystalline diamond was developed to compute the signal induced on the electrodes by the electrons and holes released by the passing particles. The simulation takes into account the crystallite structure, non-uniform trapping across the sensor, diffusion and polarization effects. It is in qualitative agreement with the data. Additional lateral electric field components result from the non-uniform trapping of charges in the bulk. These provide a good explanation for the large residuals observed.
Status of the R&D activity on diamond particle detectors Adam, W.; Bellini, B.; Berdermann, E. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
09/2003, Letnik:
511, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Chemical Vapor Deposited (CVD) polycrystalline diamond has been proposed as a radiation-hard alternative to silicon in the extreme radiation levels occurring close to the interaction region of the ...Large Hadron Collider. Due to an intense research effort, reliable high-quality polycrystalline CVD diamond detectors, with up to
270
μm
charge collection distance and good spatial uniformity, are now available. The most recent progress on the diamond quality, on the development of diamond trackers and on radiation hardness studies are presented and discussed.
AbstractChemical Vapor Deposition (CVD) diamond has been discussed extensively as an alternative sensor material for use very close to the interaction region of the LHC and other machines where ...extreme radiation conditions exist. During the last seven years the RD42 collaboration has developed diamond detectors and tested them with LHC electronics towards the end of creating a device usable by experiments. The most recent results of this work are presented. Recently, a new form of CVD diamond has been developed: single crystal CVD diamond which resolves many of the issues associated with poly-crystalline CVD material. The first tests of this material are also presented.
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