Generation of terawatt 10-fs blue pulses by compensation for pulse-front distortion in broadband frequency doubling

Pulse-front distortion as a result of broadband frequency doubling (BFD) has been compensated for over a 3-cm beam diameter by use of a telescope image relay system. As a result, distortion-free blue pulses with a peak power of 1.4 TW and a pulse width of 10 fs have been generated with a 10-Hz Ti:sapphire laser by use of this modified BFD configuration.     

Nuclear Spin Orientation Created in Heavy Ion Collisions and the Sign of the Q Moment of 13B

The momentum dependences of the nuclear spin polarization P and alignment A of ¹³B(, T _1/2 = 17.36 ms) produced in the 100A MeV ¹⁵N + Be collisions have been measured by detecting β-ray asymmetry. Because both the P and A were significantly smaller than the prediction from a simple kinematical model, some relaxation mechanisms must be take into account. Comparing the signs of the observed alignment of ¹²B, the sign of the quadrupole coupling constant eqQ of ¹³B in TiO₂ was determined to be positive.     

Generation of subterawatt sub-10-fs blue pulses at 1-5 kHz by broadband frequency doubling

Blue pulses with durations of 8.5 fs are generated by broadband frequency doubling of subterawatt Ti:sapphire laser systems at 1-5-kHz repetition rates. The average powers are 1.6 W at 5 kHz and 1.9 W at 1 kHz. The peak power is 0.16 TW with a duration of 12 fs at 1 kHz.     

Generation of vacuum-ultraviolet light by an optically contacted,prism-coupled KBe2BO3F2 crystal

We have demonstrated the second harmonic of a frequency-tripled Nd:YVO4 laser with 2.5-mW quasi-cw output by using an optically contacted, prism-coupled KBe2BO3F2 crystal. We also achieved the second harmonic with a frequency-doubled single-mode Ti:sapphire laser at 172.5 nm and sum-frequency mixing with a dual-wavelength Ti:sapphire laser at 163.3 nm. These wavelengths are to our knowledge the shortest obtained by use of nonlinear crystals for second-harmonic generation and sum-frequency mixing, respectively.     

On-line isotope separation of projectile fragments produced in relativistic heavy-ion reactions

A new on-line isotope separator was constructed and used successfully for the study on short-lived isotopes at the Bevalac at Lawrence Berkeley Laboratory. The isotopes were produced through projectile fragmentation processes of high energy heavy-ion reactions. Various isotopes were rigidity-separated by use of a beam line and, finally, the desired single isotope was range analyzed to stop in a catcher. A large number of β-emitting²¹F nuclei were successfully collected and the nuclear lifetime was determined by detecting β-rays.     

Preparation of [23]cyclophane-1,2-diones by the reaction of 3,6;12,15-Di-1,4-benzo[6.6](3,4)-1,2,5-thiadiazolocyclophanes with grignard reagents

3,6;12,15-Di-1,4-benzo[6.6](3,4)-1,2,5-thiadiazolocyclophanes 1a-c were prepared starting from 3,4-di-p-tolyl-1,2,5-thiadiazole 3 and converted into [2³]cyclophane-1,2-diones 2a-c by the reaction with Grignard reagents.     

Electric field gradient at 12 N implanted into ZnO

The nuclear quadrupole interaction of short-lived β-emitter ¹²N(I?=?1, T _1/2?=?11 ms) implanted into a ZnO single crystal has been studied by means of the β-NMR method. We have observed a quadrupole splitting of ¹²N in ZnO at room temperature, from which the electric field gradient (EFG) q?=?+?(8.6 ±1.1) ×10¹⁹ V/m² was deduced assuming axially symmetric EFG with respect to the crystalline c axis. A first principle calculation does not reproduce the data under assumption of the lattice location of ¹²N at the oxygen substitutional site.     

Coherent quasi-cw 153 nm light source at 33 MHz repetition rate

We present a quasi-cw laser in a vacuum ultraviolet region at megahertz repetition rate. The narrowband pulses generated from an ytterbium-fiber laser system at 33 MHz repetition rate at the central wavelength of 1074 nm are frequency-converted by successive stages of LiB(3)O(5) crystals and KBe(2)BO(3)F(2) crystals. The generated radiation at 153 nm has the shortest wavelength achieved through phase-matched frequency conversion processes in nonlinear optical crystals to our knowledge.     

A morphometric approach for the accurate solvation thermodynamics of proteins and ligands

We have developed a versatile method for calculating solvation thermodynamic quantities for molecules, starting from their atomic coordinates. The contribution of each atom to the thermodynamic quantities is estimated as a linear combination of four fundamental geometric measures of the atomic species, which are defined by Hadwiger's theorem, and the coefficients reflecting their solvation properties. This treatment enables us to calculate the solvation free energy with high accuracy despite of the limited computational load. The method can readily be applied to macromolecules in an all‐atom molecular model, allowing the stability of these molecules' structures in solution to be evaluated. © 2013 Wiley Periodicals, Inc.