Please note, due to essential maintenance online transactions will not be possible between 02:30 and 04:00 BST, on Tuesday 17th September 2019 (22:30-00:00 EDT, 17 Sep, 2019). We apologise for any inconvenience.
To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The results of the development of the ITEP accelerator carbon ion injector based on a repetition-rate CO2 laser ion source are described. The improvement includes a modified pulsed HV-feeding generator for the discharge formation in the laser gas mixture. The advanced discharge module ensures essential increase of the laser active volume and specific electrical deposition energy. The comparative computer simulations of the discharge characteristics for the improved and the prototype lasers are applied. The design and the output spatial-temporal parameters of the free-running laser “Malish-M” are shown, so the significant increase of the laser power is reached. The spatial characteristics of the laser beam obtained with diffraction calculations are compared to measured radial distribution of the energy density. The target laser intensity and the different channels of the energy loss of the laser beam in the optical scheme are estimated. Finally, the output C4+ current trace of heavy ion injector as well as the injector scheme are shown.
In this article, we present the results of the laser ion source
(LIS) for heavy ion high charge state Institute of Theoretical
and Experimental Physics terawatt accumulator facility. This
LIS is a duty ion source of C+4 for the injector.
The main parameters of CO2 laser, vacuum target chamber,
ion beam high voltage extraction system, and low energy beam
transport line are shown. The stability of the LIS operation
is discussed and measured ion beam parameters (ion current,
pulse duration, emittance) for different charge states are
presented. After the upgrading of the laser cavity, high voltage
capacitors, and spark gaps and the installation of a new catalyst
regenerator system, the CO2 laser became much more
stable and allows long term operation. LIS works about 1 ×
106 shots without intervention.
The construction of the Terawatt Accumulator (TWAC) facility
is nearly completed at the ITEP in Moscow. All the major milestones
have been successfully passed with a beam of carbon ions, except
for the final result (the high power beam accumulation), which
is on the way. The beam of C4+ ions delivered by
the laser ion source is accelerated up to the energy of 300
MeV/amu by two steps—in the linear injector I3 and
in the booster synchrotron UK. The accelerated beam is extracted
from the UK ring and transferred to the U10 accumulator ring.
Non-Liouvillian stripping technique (C4+ ⇒
C6+) is applied for stacking of C6+ batches
into the accumulator ring U10. First experiments with extracted
beam of ions have started in 2002. Status of the TWAC components,
current results of activities aiming at mastering the ion beam
stacking technique, and outlook for the TWAC advance are presented.
The project ITEP-TWAC (Tera Watt Accumulator) being
in progress at ITEP (Moscow) requires He-like ions for
non-Liouvillean injection into the storage ring to accumulate
≈2·1013 particles with medium masses
up to 59Co25+. Powerful lasers were
found to be the best choice for those ions production.
This work presents the experimental results of highly charge
ion generation in plasmas produced by the second harmonic
of Nd-glass laser facility with a total energy E
≤ 50 J and pulse duration of about 2.5 ns at GPI (Moscow).
Ti and Ta targets were under investigation. An electrostatic
ion energy analyzer and an ion charge collector were used
to measure the ion charge state spectra at a 3-m distance
from the targets. 5·107 He-like Ti ions
per cm2 within 1 μs pulse as well as 107
Ta+41 per cm2 within 0.8 μs were
Demonstration of matching a laser ion source to the GSI RFQ-Maxilac linear accelerator and the acceleration of a 1.8-mA current beam of Ta10+ ions up to 45 keV/u energy is presented. A 10J/μs CO2 laser has been used to produce a hot plasma plume, emitting highly charged tantulum ions. The correct geometry and potential distribution of the matching section has been designed in accordance with the results of computer simulations by using the AXCEL code. Measurements of the charge state distribution of the accelerated beam indicate that it contains about 70% Ta10+ and 30% Ta11+ ions.
This paper describes the first results of a feasibility study undertaken at CERN to determine whether a laser-produced plasma can be used as a source of intense highly charged heavy ion beams. A variety of important measurements have been made, and the results are encouraging. Furthermore, a beam of highly charged light ions produced by the laser ion source has been accelerated successfully in a radio frequency quadrupole (RFQ) structure.
Results are presented of experiments on ion production from Ta targets using a short pulse (350–600 ps in focus) illumination with focal power densities exceeding 1014 Wcm-2 at the wavelength of an iodine photodissociation laser (1.315 μm) and its harmonics. Strong evidence of the existence of tantalum ions with the charge state +45 near the target surface was obtained by X-ray spectroscopy methods. The particle diagnostics point to the existence of frozen high charge states (<53+) of Ta ions in the far expansion zone at about 2 m from the target. The measured charge state-ion energy distribution indicates the highest energy (>4 MeV) for the highest observed charge states. A tentative theoretical explanation of the observed anomalous charge state freezing phenomenon in the expanding plasma produced by a subnanosecond laser pulse is given.
The present paper presents experimental results of the transverse and longitudinal phase volume for the expanding multicharged ions in laser produced plasma, created by focusing a CO2-laser (beam) onto a Pb207 target. The total number of Pb207 ions (with Z = 1 or 2 and Z = 6), the ion current duration and amplitude at a distance of 1 m from the laser target within 10−2 steradians are determined. The measured experimental parameters of the laser heavy ion source are compared with the driver requirement for the heavy ion inertial fusion (HIIF) programme.
The phenomena observed in the experiment confirm the results of numerical calculations using a two temperature hydrodynamic programme.
Email your librarian or administrator to recommend adding this to your organisation's collection.