As nuclear and particle physics facilities move to higher intensities, the detectors used there must be more radiation tolerant. Diamond is in use at many facilities due to its inherent radiation ...tolerance and ease of use. In this article we present our radiation tolerance measurements of the highest quality polycrystalline Chemical Vapor Deposition (pCVD) diamond material for irradiations from a range of proton energies, pions and neutrons up to a fluence of 2×1016particles/cm2. We have measured the damage constant as a function of energy and particle species and compared it with theoretical models. We also present measurements of the rate dependence of pulse height for non-irradiated and irradiated pCVD diamond pad and pixel detectors, including detectors tested over a range of particle fluxes up to 20 MHz/cm2 with both pad and pixel readout electronics. Our test beam results indicate a 2% upper limit to the pulse height dependence of unirradiated and neutron irradiated pCVD diamond detectors leading to the conclusion that the pulse height in pCVD diamond detectors is, at most, minimally dependent on the particle flux.
Abstract
In stars, the fusion of
$$^{22}$$
22
Ne and
$$^4$$
4
He may produce either
$$^{25}$$
25
Mg, with the emission of a neutron, or
$$^{26}$$
26
Mg and a
$$\gamma $$
γ
ray. At high temperature, ...the (
$$\alpha ,n$$
α
,
n
) channel dominates, while at low temperature, it is energetically hampered. The rate of its competitor, the
$$^{22}$$
22
Ne(
$$\alpha $$
α
,
$$\gamma $$
γ
)
$$^{26}$$
26
Mg reaction, and, hence, the minimum temperature for the (
$$\alpha ,n$$
α
,
n
) dominance, are controlled by many nuclear resonances. The strengths of these resonances have hitherto been studied only indirectly. The present work aims to directly measure the total strength of the resonance at
$$E_{\text {r}}$$
E
r
= 334 keV (corresponding to
$$E_{\text {x}}$$
E
x
= 10949 keV in
$$^{26}$$
26
Mg). The data reported here have been obtained using high intensity
$$^4$$
4
He
$$^+$$
+
beam from the INFN LUNA 400 kV underground accelerator, a windowless, recirculating, 99.9% isotopically enriched
$$^{22}$$
22
Ne gas target, and a 4
$$\pi $$
π
bismuth germanate summing
$$\gamma $$
γ
-ray detector. The ultra-low background rate of less than 0.5 counts/day was determined using 63 days of no-beam data and 7 days of
$$^4$$
4
He
$$^+$$
+
beam on an inert argon target. The new high-sensitivity setup allowed to determine the first direct upper limit of 4.0
$$\,\times \,$$
×
10
$$^{-11}$$
-
11
eV (at 90% confidence level) for the resonance strength. Finally, the sensitivity of this setup paves the way to study further
$$^{22}$$
22
Ne(
$$\alpha $$
α
,
$$\gamma $$
γ
)
$$^{26}$$
26
Mg resonances at higher energy.
We have measured the radiation tolerance of poly-crystalline and single-crystalline diamonds grown by the chemical vapor deposition (CVD) process by measuring the charge collected before and after ...irradiation in a 50 m pitch strip detector fabricated on each diamond sample. We irradiated one group of sensors with 800 MeV protons, and a second group of sensors with 24 GeV protons, in steps, to protons cm−2 and protons cm−2 respectively. We observe the sum of mean drift paths for electrons and holes for both poly-crystalline CVD diamond and single-crystalline CVD diamond decreases with irradiation fluence from its initial value according to a simple damage curve characterized by a damage constant for each irradiation energy and the irradiation fluence. We find for each irradiation energy the damage constant, for poly-crystalline CVD diamond to be the same within statistical errors as the damage constant for single-crystalline CVD diamond. We find the damage constant for diamond irradiated with 24 GeV protons to be and the damage constant for diamond irradiated with 800 MeV protons to be . Moreover, we observe the pulse height decreases with fluence for poly-crystalline CVD material and within statistical errors does not change with fluence for single-crystalline CVD material for both 24 GeV proton irradiation and 800 MeV proton irradiation. Finally, we have measured the uniformity of each sample as a function of fluence and observed that for poly-crystalline CVD diamond the samples become more uniform with fluence while for single-crystalline CVD diamond the uniformity does not change with fluence.
The first module of a Ring Imaging Cherenkov detector has been recently installed on the CLAS12 spectrometer at the Jefferson Laboratory (JLab) to provide the experiment with kaon identification in ...the momentum range between 3 and 8 GeV/c. The detector adopts a hybrid optics solution with aerogel radiator, light planar and spherical mirrors and highly-segmented photon detectors. We report here on the assembly and installation of the RICH and we show the first preliminary results obtained during the commissioning of the detector and the first physics data taking.
Laser beam studies of RPC behaviour in avalanche mode Golovatyuk, V.; Grancagnolo, F.; Perrino, R.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2003, Letnik:
508, Številka:
1-2
Journal Article
Recenzirano
Primary ionization is created inside the gas gap of a small size (10×20cm2) RPC, analogous to the RPC of the ATLAS muon detector, by focusing a pulsed (width ⩽0.5ns) nitrogen laser beam (transverse ...diameter ≈15μm). With this set-up we can characterize the behaviour of the RPC by measuring such parameters as drift velocity and gas amplification. For an ATLAS-like gas mixture (97% C2H2F4, 3% isobutane and a small addition of SF6), we have evidence of a space charge influence on RPC rate capability.
We introduce the LUNA neutron detector array developed for the investigation of the 13C(α, n)16O reaction towards its astrophysical s-process Gamow peak in the low-background environment of the ...Laboratori Nazionali del Gran Sasso (LNGS). Eighteen 3He counters are arranged in two different configurations (in a vertical and a horizontal orientation) to optimize neutron detection efficiency, target handling and target cooling over the investigated energy range Eα,lab=300−400 keV (En=2.2−2.6MeV in emitted neutron energy). As a result of the deep underground location, the passive shielding of the setup and active background suppression using pulse shape discrimination, we reached a total background rate of 1.23±0.12 counts/hour. This resulted in an improvement of two orders of magnitude over the state of the art allowing a direct measurement of the 13C(α, n)16O cross-section down to Eα,lab=300 keV. The absolute neutron detection efficiency of the setup was determined using the 51V(p,n)51Cr reaction and an AmBe radioactive source, and completed with a Geant4 simulation. We determined a (34 ± 3)% and (38 ± 3)% detection efficiency for the vertical and horizontal configurations, respectively, for En=2.4MeV neutrons.
In order to ensure that the resistive plate chambers used in the ATLAS experiment will not show, during their operation, any abnormal aging effect which could degrade their performances, an aging ...test is being performed at X5-GIF, CERN's gamma irradiation facility. In this paper, the latest results are presented, together with an example of successful damage recovery technique.
Ageing test of the ATLAS RPCs at X5-GIF Aielli, G.; Alviggi, M.; Ammosov, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2004, Letnik:
533, Številka:
1-2
Journal Article
Recenzirano
An ageing test of three ATLAS production RPC stations is in course at X5-GIF, the CERN irradiation facility. The chamber efficiencies are monitored using cosmic rays triggered by a scintillator ...hodoscope. Higher statistics measurements are made when the X5 muon beam is available. We report here the measurements of the efficiency versus operating voltage at different source intensities, up to a maximum counting rate of about 700Hz/cm2. We describe the performance of the chambers during the test up to an overall ageing of 4 ATLAS equivalent years corresponding to an integrated charge of 0.12C/cm2, including a safety factor of 5.
Diamond detector technology, status and perspectives Alexopoulos, A.; Artuso, M.; Bachmair, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2019, Letnik:
924, Številka:
C
Journal Article
Recenzirano
Odprti dostop
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. The startup of the LHC in 2015 brought a new milestone where the first polycrystalline CVD (pCVD) diamond pixel modules were installed in an LHC experiment and successfully began operation. The RD42 collaboration at CERN is leading the effort to develop polycrystalline CVD diamond as a material for tracking detectors operating in extreme radiation environments. The status of the RD42 project with emphasis on recent beam test results is presented.
•Successful operation of the first pCVD diamond planar pixel detector in the ATLAS experiment at the LHC.•Demonstration that the average signal pulse height of pCVD diamond detectors irradiated up to 5×014n∕cm2 is independent of the particle flux up to ∼20 MHz/cm2.•Successful fabrication and operation of the first pCVD diamond 3D pixel detector with 50 micron × 50 micron cells read out with CMS pixel electronics with 3 cell × 2 cell ganging into pixels to match the electronics.•Demonstration that in the pCVD diamond 3D pixel device the efficiency for a MIP was 99% when operating with a 1500 e threshold.
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