Understanding the effect of radiation on the functional properties of epoxy resins is crucial for their application in future particle accelerators like the Future Circular Collider (FCC). We compare ...the irradiation induced aging rates of six epoxy resin systems that can be used for the vacuum impregnation of magnet coils. Aging is assessed based on Dynamical Mechanical Analysis (DMA), 3-point bending and outgassing tests. DMA storage and loss moduli evolutions reveal the effect of the competing influence of cross-linking and chain scission on the glass transition temperature ( T g ). The same proton and gamma irradiation dose has a similar effect on the thermomechanical epoxy resin properties. Aging rates differ strongly for the different resins, and the fastest aging is observed for the MY750 resin system, which T g decreases with a rate of about minus 9 °C/MGy.
The TOTEM collaboration at the CERN LHC has measured the differential cross-section of elastic proton–proton scattering at
s
=
8
TeV
in the squared four-momentum transfer range
0.2
GeV
2
<
|
t
|
<
...1.9
GeV
2
. This interval includes the structure with a diffractive minimum (“dip”) and a secondary maximum (“bump”) that has also been observed at all other LHC energies, where measurements were made. A detailed characterisation of this structure for
s
=
8
TeV
yields the positions,
|
t
|
dip
=
(
0.521
±
0.007
)
GeV
2
and
|
t
|
bump
=
(
0.695
±
0.026
)
GeV
2
, as well as the cross-section values,
d
σ
/
d
t
dip
=
(
15.1
±
2.5
)
μ
b
/
GeV
2
and
d
σ
/
d
t
bump
=
(
29.7
±
1.8
)
μ
b
/
GeV
2
, for the dip and the bump, respectively.
Abstract
The TOTEM collaboration at the CERN LHC has measured the differential cross-section of elastic proton–proton scattering at
$$\sqrt{s} = 8\,\mathrm{TeV}$$
s
=
8
TeV
in the squared ...four-momentum transfer range
$$0.2\,\mathrm{GeV^{2}}< |t| < 1.9\,\mathrm{GeV^{2}}$$
0.2
GeV
2
<
|
t
|
<
1.9
GeV
2
. This interval includes the structure with a diffractive minimum (“dip”) and a secondary maximum (“bump”) that has also been observed at all other LHC energies, where measurements were made. A detailed characterisation of this structure for
$$\sqrt{s} = 8\,\mathrm{TeV}$$
s
=
8
TeV
yields the positions,
$$|t|_{\mathrm{dip}} = (0.521 \pm 0.007)\,\mathrm{GeV^2}$$
|
t
|
dip
=
(
0.521
±
0.007
)
GeV
2
and
$$|t|_{\mathrm{bump}} = (0.695 \pm 0.026)\,\mathrm{GeV^2}$$
|
t
|
bump
=
(
0.695
±
0.026
)
GeV
2
, as well as the cross-section values,
$$\left. {\mathrm{d}\sigma /\mathrm{d}t}\right| _{\mathrm{dip}} = (15.1 \pm 2.5)\,\mathrm{{\mu b/GeV^2}}$$
d
σ
/
d
t
dip
=
(
15.1
±
2.5
)
μ
b
/
GeV
2
and
$$\left. {\mathrm{d}\sigma /\mathrm{d}t}\right| _{\mathrm{bump}} = (29.7 \pm 1.8)\,\mathrm{{\mu b/GeV^2}}$$
d
σ
/
d
t
bump
=
(
29.7
±
1.8
)
μ
b
/
GeV
2
, for the dip and the bump, respectively.
In this research, the anneal induced transformations of radiation defects have been studied in n-type and p-type CZ and FZ Si samples, irradiated with relativistic protons (24GeV/c) and pions ...(300MeV/c) using particle fluences up to 3 × 1016cm−2. The temperature dependent carrier trapping lifetime (TDTL) spectroscopy method was combined with measurements of current deep level transient spectroscopy (DLTS) to trace the evolution of the prevailing radiation defects. The contactless TDTL technique has been shown to be preferential when the radiation induced trap density approaches or exceeds the dopant concentration and when it is necessary to avoid modification of a detector structure due to annealing processes at elevated temperatures. The deep level spectra were complementarily examined by using DLTS spectroscopy on Schottky diodes made of irradiated Si wafer fragments. The dominant radiation defects and their transform paths under isothermal and isochronal anneals have been revealed. A good agreement between the DLTS and TDTL spectra has been obtained.
The proton–proton elastic differential cross section
d
σ
/
d
t
has been measured by the TOTEM experiment at
s
=
2.76
TeV
energy with
β
∗
=
11
m
beam optics. The Roman Pots were inserted to 13 times ...the transverse beam size from the beam, which allowed to measure the differential cross-section of elastic scattering in a range of the squared four-momentum transfer (|
t
|) from 0.36 to
0.74
GeV
2
. The differential cross-section can be described with an exponential in the |
t
|-range between 0.36 and
0.54
GeV
2
, followed by a diffractive minimum (dip) at
|
t
dip
|
=
(
0.61
±
0.03
)
GeV
2
and a subsequent maximum (bump). The ratio of the
d
σ
/
d
t
at the bump and at the dip is
1.7
±
0.2
. When compared to the proton–antiproton measurement of the D0 experiment at
s
=
1.96
TeV
, a significant difference can be observed. Under the condition that the effects due to the energy difference between TOTEM and D0 can be neglected, the result provides evidence for the exchange of a colourless C-odd three-gluon compound state in the
t
-channel of the proton–proton and proton–antiproton elastic scattering.
At the CERN Proton Synchrotron (PS) accelerator complex, two experimental zones allow the irradiation of samples in a 23 GeV pure proton beam and in a secondary particle environment dominated by ...1-MeV neutrons and gamma rays. In this paper, a review of the operative irradiation systems named IRRAD1 and IRRAD2 is presented, as well as the improvements in the techniques used for the beam characterizations and dosimetry
The BPW34 p-i-n diode was characterized at CERN in view of its utilization as radiation monitor at the LHC to cover the broad 1-MeV neutron equivalent fluence (Phi eq ) range expected for the LHC ...machine and experiments during operation. Electrical measurements for both forward and reverse bias were used to characterize the device and to understand its behavior under irradiation. When the device is powered forward, a sensitivity to fast hadrons for Phi eq > 2 times10 12 cm -2 has been observed. With increasing particle fluences the forward I- V characteristics of the diode shifts towards higher voltages. At Phi eq > 3times10 13 cm -2 , the forward characteristic starts to bend back assuming a thyristor-like behavior. An explanation for this phenomenon is given in this article. Finally, detailed radiation-response curves for the forward bias-operation and annealing studies of the diode's forward voltage are presented for proton, neutron and gamma irradiation.
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