[en] The low-volt nonstationary electron emission from the one-wall carbon nanotubes originating after the passage of the high auto-emission current is identified. It is assumed that this emission represents the exoelectron emission connected with the mechanical stresses and defects originating in the nanotubes under the impact of the electrostatic forces effecting the nanotubes in the strong electric field

[en] The effect of removing zinc from the brass particles by the laser irradiation of the their suspension in ethanol is experimentally identified. The nanoparticles absorption spectra study shows that in process of irradiation the brass nanoparticles are transformed into the copper nanoparticles. The obtained results are interpreted from the viewpoint of the nanoparticles phase diagram modification, conditioned by the pressure growth. The pressure is caused firstly due to the nanoparticles small radius and secondly - due to the surrounding liquid steam pressure by the nanoparticles laser heating

No abstract available

[en] A new BPM system, based on resonant cavities, has been developed for measuring the transverse position of very low-intensity electron beams delivered to Experimental Hall B at the Continuous Electron Beam Accelerator Facility (CEBAF) in Newport News. VA. The system requirements called for measuring down to 1 nA with a 100 m m resolution. The actual system is much better: it can measure down to 100 pA at the 100 m m required resolution. A 100 pA beam yields about 1 electron per bunch. Each 1 nA BPM utilizes three resonant RF cavities to determine the position of the beam: one cavity sensitive to X position, a second cavity sensitive to Y position, and a third cavity which measures intensity. The position cavities operate at room temperature in a dipole type mode at 1497 MHz and contain internal field perturbing rods in an arrangement similar to that of the CEBAF rf Separator cavities. The position cavities are electron beam welded assemblies made of copper plated stainless steel. The RF output signal from each cavity is processed using a down-converter and a DSP based commercial lock-in amplifier operating at 100 kHz. The lock-in amplifiers connect to the EPICS control system via an IEEE 488 bus. System features under development include intensity and position modulation measurement capabilities. This paper provides measured performance results and an updated overview of the installed and operational 1 nA BPM system. copyright 1998 American Institute of Physics

[en] After six years of construction, the French GANIL (Grand Accelerateur National d'Ions Lourds) machine at Caen recently came on stream, accelerating a 50 nA beam of argon ions to an energy of 44 MeV/nucleon. (100 nA beams are now handled.) Today's physics interests amply confirm the thinking behind the launching of the GANIL project ten years ago. (orig./HSI).

[en] A scheme is developed which permits to control continuously the average current of a linear electron accelerator beam with the output to the figure indicator. The scheme measures the average current component of pulses, coming from the output of the induction pickup-of-flight and is used at 300 MeV accelerator. The low limit of measured currents is 10^-8 A, the transformation error is no greater than +-1%. The device can be used at any charged particles accelerator, where the measurement of the average beam current is necessary

No abstract available

[en] A ≤ nA external beam of 50 to 200 MeV is required for certain physics and medical experiments at the same time as 200 μA is being accelerated for meson production. A mode-locked laser, synchronized with the cyclotron rf, can produce a 20 nA parasitic H⁰ beam for continuous extraction. The best available Nd:YAG or Nd:YLF laser (Av. Pwr. 15 W) mode-locked at a harmonic of the cyclotron rf falls short of the required intensity by a factor of about 50. An optical delay line could trap the mode-locked pulse train to achieve the required intensity. The optical delay line is a near-concentric resonator installed half above and half below the beam plane and in which all trapped pulses cross the midplane in synchronism with the cyclotron beam bunches. An analysis of the delay line is presented in terms of the transfer matrix for one round trip in the periodic focusing system formed by the end mirrors of the resonator. An enhancement factor ≥55 is possible with 80 trapped pulses if the mirror reflectively ≥ 99%

[en] A novel ion projection lithography (IPL) technique called maskless-micro-beam reduction lithography (MMRL) is being developed at the Lawrence Berkeley National Laboratory. Instead of a thin stencil mask, this new ion projection lithography scheme utilizes a thicker universal pattern generator (or beam forming electrode) which contains switchable beamlets. Both single aperture and nine-aperture beam extraction systems have been used to test the switching scheme. In the single aperture case, an ion beam current of 23 nA was extracted and successfully turned off when a positive voltage was applied on the second electrode. For the nine-hole system, ion beams were switched on and off selectively and independently from each other. It has been demonstrated that electron beam switching can be achieved in a similar manner

[en] The TRIUMF polarized ion source has been in operation for 6 months. It is of the Lamb-shift type and uses the Sona method for enhancing the polarization. It typically produces 200 nanoamperes of 75 percent polarized H^- ions at the injection energy of 300 kilovolts. Transmission through the injection line is approximately 80 percent, and up to 30 nanoamperes of beam have been delivered on target in the energy range of 200 MeV to 500 MeV