Test of Time-Reversal Invariance at COSY (TRIC) Eversheim, D; Valdau, Yu; Lorentz, B
International journal of modern physics. Conference series,
2016, Letnik:
40, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
At the Cooler Synchrotron COSY a novel (P-even, T-odd) null test of time-reversal invariance to an accuracy of 10
−
6
is planned as an internal target transmission experiment. The parity conserving ...time-reversal violating observable is the total cross-section asymmetry A
y,xz
. This quantity is measured using a polarized proton beam with an energy of 135 MeV and an internal tensor polarized deuteron target from the PAX atomic beam source. The reaction rate will be determined by the lifetime of the beam. Consequently, the accuracy of the current measurement of the circulating proton beam is crucial for this experiment. Thus, the cooler synchroton ring serves as an ideal forward spectrometer, as a detector, and an accelerator.
Diffusion of implanted
57Co in ZnO has been determined in the temperature range 660–950
°C using the modified radiotracer technique. The diffusion was found to follow the Arrhenius type relation with ...an activation enthalpy of (2.9
±
0.3)
eV and a pre-exponential factor of 3
×
10
−
4
m
2/s. Supported by diffusion data and conclusions provided in the literature, it is proposed that cobalt diffuses substitutionally in ZnO.
Ferroelectric lithium niobate crystals offer a great potential for applications in modern optics. To provide powerful optical components, tailoring of key material parameters, especially of the ...refractive index
n
and the ferroelectric domain landscape, is required. Irradiation of lithium niobate crystals with accelerated ions causes strong structured modifications in the material. The effects induced by low-mass, high-energy ions (such as
3
He with 41 MeV, which are not implanted, but transmit through the entire crystal volume) are reviewed. Irradiation yields large changes of the refractive index
Δn
, improved domain engineering capability within the material along the ion track, and waveguiding structures. The periodic modification of
Δn
as well as the formation of periodically poled lithium niobate (PPLN) (supported by radiation damage) is described. Two-step knock-on displacement processes,
3
He→Nb and
3
He→O causing thermal spikes, are identified as origin for the material modifications.
The neutrino mass experiment KATRIN requires a stability of 3 ppm for the retarding potential at - 18.6 kV of the main spectrometer. To monitor the stability, two custom-made ultra-precise ...high-voltage dividers were developed and built in cooperation with the German national metrology institute Physikalisch-Technische Bundesanstalt (PTB). Until now, regular absolute calibration of the voltage dividers required bringing the equipment to the specialised metrology laboratory. Here we present a new method based on measuring the energy difference of two Formula omittedKr conversion electron lines with the KATRIN setup, which was demonstrated during KATRIN's commissioning measurements in July 2017. The measured scale factor Formula omitted of the high-voltage divider K35 is in agreement with the last PTB calibration 4 years ago. This result demonstrates the utility of the calibration method, as well as the long-term stability of the voltage divider.
The vector and tensor polarizations of a deuteron beam have been measured using elastic deuteron-carbon scattering at 75.6 MeV and deuteron-proton scattering at 270 MeV. After their acceleration to ...1170 MeV inside the COSY ring, the polarizations of the deuterons were checked by studying a variety of nuclear reactions using a cluster target at the ANKE magnet spectrometer placed at an internal target position of the storage ring. All these measurements were consistent with the absence of depolarization during acceleration and provide us with a number of secondary standards that can be used in subsequent experiments at the facility.
PDF
