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Reduction of time and cost of proton irradiation tests on space solar cells are considered by adopting state-of-the-art proton beam technologies developed at the Japan Atomic Energy Agency (JAEA). An irradiation area of about 80mm × 40mm is achieved with excellent uniformity in current density by the uniform-beam formation technique which employs multipole magnets. The experimental result of 10 MeV-proton irradiation using this ‘flash’ (nonscanned, short-pulse) technique indicates no significant difference in the degradation trend of InGaP/GaAs/Ge triple-junction space solar cells compared to the results using our conventional beam-scanning method. The uniform-beam-formation approach enables irradiation over a time duration that is about an order of magnitude less than that required for the conventional scanned spot beam. Development of laser-driven proton beams is also being conducted at JAEA in which divergent proton yields with broad spectra similar to the space environment are typical. Laser-acceleration of protons is the result of intense irradiation of thin foil targets (such as aluminum) by high power lasers. For proton spectra that adequately simulate the space environment many irradiation tests with different specified proton energies will be unnecessary affording great simplification of complex radiation degradation prediction such as the relative damage coefficient method or the displacement damage dose method. Ground tests with a suitable compact laser-driven source can also enhance access and experiment diversity for irradiation studies. [ABSTRACT FROM PUBLISHER]

We present our study on a 87Rb atomic beam frequency standard with laser pumping and detection performed in the frame of an INTAS-CNES collaboration and in view of designing and realizing a spaceborne atomic clock with instability of ∼ 10−14 per day. [ABSTRACT FROM PUBLISHER]

We present a 2D magneto-optical trap (MOT) that uses an innovative simple optical configuration. Instead of mirrors and quarter-wave plates we use metal-coated retro-reflecting prisms so as to recycle the optical power of the cooling laser beam. We have characterised this source for three different configurations: with and without transverse magnetic field gradient, as well as with a pusher beam to produce a 2D+-MOT. The longitudinal velocity is about 25 m·s−1, with a transverse velocity spread ≤ 1 m·s−1, while the typical atomic flux density can be as much as 1.3×1014 at·s−1·m−2 for a cesium vapour pressure of ∼4×10−8 mbar in the source. We use this low velocity atomic beam, instead of thermal vapour, to load a 3D moving optical molasses that launches a continuous cold cesium fountain. We achieve a gain of a factor ∼ 20 in the fountain's atomic flux. [ABSTRACT FROM PUBLISHER]

To meet the requirement of nanoscale dimensional metrology, lengthy standards with features below 100 nanometers are indispensable instruments. Our group has successfully fabricated length standards through atom lithography. For further improvement of the quality of these standards, laser cooling of Chromium atom beam was studied through a transverse Doppler cooling scheme. Moreover, utilizing the software developing kit (SDK) of CCD camera, we developed an image collecting software, which had functions of real-time display for gray-scale image and image measure. In our experimental setup, with the software, we could detect the laser induced fluorescence spots from marginal beams to monitor and analyze the effect of laser cooling. [ABSTRACT FROM PUBLISHER]

Laser Induced Fluoresces (LIF) and laser cavity ring-down spectroscopy (CRDS) have been recently developed in our group for diagnosis of the active species (atoms, ions or radicals) in reactive plasmas. In the first experimental approach, time-resolved LIF technique was used to investigate the temporal evolutions of the number density of metastable state N2 (A) in the nanosecond pulsed post discharge in a complicated H2CO / N2 /O2 mixture. The N2 (A, v=0) state was pumped to to N2 (B, v=4) with a dye laser irradiation at 618 nm, and the subsequent fluorescence emission from N2 (B, v=4) to N2 (A, v=1) has been measured. The results indicated that the triplet meta stable state of N2 (A) has played an important role in the removal mechanism of formaldehyde in the plasma. In the second experimental arrangement, CRDS has been applied to investigate the generation and destruction of NO2 both in the air DBD discharge and nanosecond pulsed discharge plasmas. The observed oscillation of NO2 number density during the post discharge will be presented and the results will be discussed in the conference. [ABSTRACT FROM PUBLISHER]