bluuebunny/crossref_metadata_2025 huggingface dataset:
Status of the Terawatt Accumulator Accelerator project
Authors: ALEXEEV N.N. , ALEKSEEV P.N. , BALANUTSA V.N. , BEREZNITSKY S.L. , EVTICHOVICH V.N. , GORJACHEV JU.M. , KIRILLOV A.V. , KOSHKAREV D.G. , MESCHEREKOV N.D. , MILIJACHENKO A.V. , NIKITIN G.A. , NIKOLAEV V.I. , OKOROKOV I.S. , SHARKOV B.YU. , SCHEGOLEV V.A. , SOSNIN D.V. , SHUMSHUROV A.V. , VESELOV M.A. , ZAVODOV V.P. , ZAVRAZHNOV V.S. , ZENKEVICH P.R. , ZHURAVLEV A.S. , MAMAEV G.L. , KRASNOPOLSKY V.A. , KRYLOV S.JU. , PUCHKOV S.N. , TENJAKOV I.E.
Published: February 2003

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.
High-energy-density matter research at GSI Darmstadt using
intense heavy ion beams
Authors: TAHIR N.A. , SHUTOV A. , VARENTSOV D. , HOFFMANN D.H.H. , SPILLER P. , LOMONOSOV I. , WIESER J. , JACOBY J. , FORTOV V.E.
Published: February 2003

This paper presents two-dimensional numerical simulations of
heating of matter with intense heavy ion beams. It has been
shown that it is very advantageous to irradiate the target with
two different beams simultaneously, a main high intensity bunched
beam of a heavy element like uranium and an unbunched low intensity
beam of a lighter element like argon. The main beam is used
to heat the target while the second beam is used as a diagnostic
tool.

Influence of the shape of the focal spot on compression and
heating of matter has also been studied using an elliptic focal
spot with an ellipticity of 1.5 (semimajor axis is along
y-axis and is 1.5 times the semiminor axis which is
along x-axis). It has been found that the temporal
behavior of the development of density, pressure, and temperature
profiles along different directions is quite different, which
is not the case with a circular focal spot.
Studies of high energy density in matter driven by heavy
ion beams in solid targets
Authors: DEWALD E. , CONSTANTIN C. , UDREA S. , JACOBY J. , HOFFMANN D.H.H. , NIEMANN C. , WIESER J. , TAHIR N.A. , KOZYREVA A. , SHUTOV A. , TAUSCHWITZ A.
Published: February 2003

By the interaction of intense (1010
particles/500 ns) relativistic (∼300
MeV/amu) heavy ion beams with solid targets, large volumes
(several cubic millimeters) of strongly coupled plasmas are
produced at solid-state densities and temperatures of up to
1 eV, with relevance for equation-of-state (EOS) studies of
matter at high energy density and heavy ion-beam-driven inertial
confinement fusion (ICF). The time and space profile of the
ion beams, focused by the plasma lens to diameters of a minimum
of 0.5 mm in order to obtain specific energy depositions of
up to about 4 kJ/g, were measured to calculate the energy
deposition in the target. In the present work, the plasmas created
by ion beam interaction with cryogenic gas crystals and metallic
targets are studied, among other methods, by backlighting
shadowgraphy and electrical conductivity measurements. The
experiments are coupled with two-dimensional hydrodynamic simulations.
Progress in heavy ion target capsule and hohlraum design
Authors: CALLAHAN DEBRA A. , HERRMANN MARK C. , TABAK MAX
Published: February 2003

Progress in heavy ion target design over the past few years
has focused on relaxing the target requirements for the driver
and for target fabrication. We have designed a plastic (CH)
ablator capsule that is easier to fabricate and fill than the
beryllium ablator we previously used. In addition, two-dimensional
Rayleigh–Taylor instability calculations indicate that
this capsule can tolerate ablator surface finishes up to 10
times rougher than the NIF specification. We have also explored
the trade-off between surface roughness and yield as a method
for finding the optimum capsule. We have also designed two new
hohlraums: a “hybrid” target and a large-angle,
distributed radiator target. The hybrid target allows a beam
spot radius of almost 5 mm while giving gain of 55 from 6.7
MJ of beam energy in integrated Lasnex calculations. To achieve
the required symmetry with the large beam spot, internal shields
were used in the target to control the P2 and
P4 asymmetry. The large-angle, distributed
radiator target is a variation on the distributed radiator target that
allows large beam entrance angles (up to 24°). Integrated calculations
have produced 340 MJ from 6.2 MJ of beam energy in a design
that is not quite optimal, In addition, we have done a simple
scaling to understand the peak ion beam power required to compress
fuel for fast ignition using a short pulse laser.
Prospects of heavy ion fusion in cylindrical geometry
Authors: BASKO M.M. , CHURAZOV M.D. , AKSENOV A.G.
Published: February 2003

A possibility is analyzed to use direct drive cylindrical targets
in the fast ignition mode irradiated by beams of nearly relativistic
heavy ions with long ranges in matter. The minimum beam energy
required to compress the DT fuel in a 1-cm-long target to
(ρR)DT = 0.5 g/cm2,
ρDT = 100 g/cm3 is found to lie
in the range 10–15 MJ. Ignition and axial burn propagation is
achieved with a 0.2-ns, 0.4-MJ pulse of 100-GeV heavy ions. Thermonuclear
energy gains in the range 50–150 appear to be possible.
Fast ignition of the DT fuel in the cylindrical channel by
heavy ion beams
Authors: VATULIN V.V. , VINOKUROV O.A.
Published: February 2003

The so-called fast ignition mode is one way to ignite
the thermonuclear fuel in systems of inertial fusion and decrease
of the necessary energy of the driver. In the present work the
second stage of the process—the heating, the thermonuclear
burning initiation under the influence of a powerful ion pulse,
and distribution of the burning all over the rest of the
cylindrical system—is studied. The main purpose of the
presented calculations was to determine the threshold of the
fast ignition of the cylindrical DT cord by a heavy ion beam.
Evaluation of a power plant concept for fast ignition heavy
ion fusion
Authors: MEDIN S.A. , CHURAZOV M.D. , KOSHKAREV D.G. , SHARKOV B.YU. , ORLOV YU.N. , SUSLIN V.M.
Published: February 2003

The characteristics of a fast ignition heavy ion fusion (FIHIF)
power plant are preliminarily evaluated. The reactor chamber
consists of two sections: The upper smaller part is the
microexplosion section proper; the lower bigger part is the
condensation section, in which sprayed jets of coolant are
injected. The first surface of the blanket is of generally accepted
wetted porous design. The coolant is lithium-lead eutectic with
an initial surface temperature of 820 K. The mass of the evaporated
coolant just after the explosion is evaluated as 4 kg. Computation
of neutronics results in blanket energy deposition with maximum
density of the order of 108 J/m3 at the
first wall. The heat conversion system consisting of three coolant
loops provides a net efficiency of the FIHIF power plant of
0.37.
Numerical codes development issues
Authors: MARUHN J.A. , ATZENI S. , HONRUBIA J. , RAMIREZ J. , RAMIS R. , SHUTOV A. , TEMPORAL M.
Published: February 2003

An overview of the various design choices to be made for a
two-dimensional numerical code to simulate heavy ion targets
is given. We discuss such issues as the grid structure, rezoning
techniques, and the inclusion of material properties to various
degrees. This is followed by a brief discussion of the open
codes being used in the European heavy ion fusion community
with characteristic samples of their application.
Analytic model for studying heavy-ion-imploded cylindrical targets
Authors: PIRIZ A.R. , PORTUGUES R.F. , TAHIR N.A. , HOFFMANN D.H.H.
Published: February 2003

We have developed an analytical model for the implosion of
a heavy ion beam driven multilayered cylindrical target. The
target consists of a thick metallic shell, typically made of
lead which is filled with a low density material, for example
frozen hydrogen, and it is axially irradiated with a heavy ion
beam with an annular focal spot. The model describes the expansion
of the absorption region, the implosion of the pusher, the
trajectories of the incident and reflected shocks and the final
quasi-isentropic compression. The model is expected to be very
helpful to optimize detailed simulations of such problems which
are of close relevance to the GSI plasma physics experimental
program, planned for the future upgraded accelerator facilities.
End-to-end simulation: The front end
Authors: HABER I. , BIENIOSEK F.M. , CELATA C.M. , FRIEDMAN A. , GROTE D.P. , HENESTROZA E. , VAY J.-L. , BERNAL S. , KISHEK R.A. , O'SHEA P.G. , REISER M. , HERRMANNSFELDT W.B.
Published: February 2003

For the intense beams in heavy ion fusion accelerators, details
of the beam distribution as it emerges from the source region
can determine the beam behavior well downstream. This occurs
because collective space-charge modes excited as the beam is
born remain undamped for many focusing periods. Traditional
studies of the source region in particle beam systems have
emphasized the behavior of averaged beam characteristics, such
as total current, rms beam size, or emittance, rather than the
details of the full beam distribution function that are necessary
to predict the excitation of the collective modes. Simulations
of the beam in the source region and comparisons to experimental
measurements at Lawrence Berkeley National Laboratory and the
University of Maryland are presented to illustrate some of the
complexity in beam characteristics that has been uncovered as
increased attention has been devoted to developing a detailed
understanding of the source region. Also discussed are methods
of using the simulations to infer characteristics of the beam
distribution that can be difficult to measure directly.
The high current experiment: First results
Authors: SEIDL P.A. , BACA D. , BIENIOSEK F.M. , FALTENS A. , LUND S.M. , MOLVIK A.W. , PROST L.R. , WALDRON W.L.
Published: February 2003

The High Current Experiment (HCX) is being assembled at Lawrence
Berkeley National Laboratory as part of the U.S. program to
explore heavy ion beam transport at a scale representative of
the low-energy end of an induction linac driver for fusion energy
production. The primary mission of this experiment is to
investigate aperture fill factors acceptable for the transport
of space-charge dominated heavy ion beams at high space-charge
intensity (line-charge density ∼ 0.2 μC/m) over
long pulse durations (>4 μs). This machine will test
transport issues at a driver-relevant scale resulting from
nonlinear space-charge effects and collective modes, beam centroid
alignment and beam steering, matching, image charges, halo,
lost-particle induced electron effects, and longitudinal bunch
control. We present the first experimental results carried out
with the coasting K+ ion beam transported through
the first 10 electrostatic transport quadrupoles and associated
diagnostics. Later phases of the experiment will include more
electrostatic lattice periods to allow more sensitive tests
of emittance growth, and also magnetic quadrupoles to explore
similar issues in magnetic channels with a full driver scale
beam.
A 1.8-MeV K+ injector for the high current beam
transport experiment
Authors: KWAN J.W. , BIENIOSEK F.M. , HENESTROZA E. , PROST L. , SEIDL P.
Published: February 2003

For the High Current Beam Transport Experiment (HCX) at Lawrence
Berkeley National Laboratory, an injector is required to deliver
up to 1.8 MV of 0.6 A K+ beam with an emittance of
≈1 π-mm-mrad. We have successfully operated a 10-cm-diameter
surface ionization source together with an electrostatic quadrupole
(ESQ) accelerator to meet these requirements. The pulse length
is ≈4 μs, firing at once every 10–15 s. By optimizing
the extraction diode and the ESQ voltages, we have obtained
an output beam with good current density uniformity, except
for a small increase near the beam edge. Characterization of
the beam emerging from the injector included measurements of
the intensity profile, beam imaging, and transverse phase space.
These data along with comparison to computer simulations provide
the knowledge base for designing and understanding future HCX
experiments.
Scheme for direct plasma injection into an RFQ linac
Authors: OKAMURA M. , KATAYAMA T. , JAMESON R.A. , TAKEUCHI T. , HATTORI T. , KASHIWAGI H.
Published: February 2003

A new efficient injection method from a laser ion source to
a Radio Frequency Quadropole (RFQ) was proposed and is being
tested in RIKEN, Japan. A laser plasma is induced just before
the entrance of the RFQ and is injected directly into the RFQ
channel. Using an existing RFQ, first verification tests have
been completed successfully. Finally, the preliminary
specifications for the first RFQ dedicated to the new injection
scheme are presented.
Laser ion source of multicharged ions for ITEP accumulator facility
Authors: MESCHERYAKOV N.D. , ALEXEEV N.N. , BALABAEV A.N. , KONDRASHEV S.A. , KONYUKOV K.V. , NIKOLAEV V.I. , ROUDSKOY I.V. , SAVIN S.M. , SHARKOV B.Yu. , SHUMSHUROV A.V.
Published: February 2003

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.
Electron cooling system for ITEP ion storage ring
Authors: ZENKEVICH P.R. , ALEXEEV N.N. , BARKHUDARYAN A.V. , BOLSHAKOV A.Ye. , KOSHKAREV D.G. , SHARKOV Yu.V. , BYKOVSKY V.F. , KOROTAEV Yu.V. , MESHKOV I.N. , SIDORIN A.O. , SMIRNOV A.V. , SYRESIN Ye.M. , TITKOVA I.V.
Published: February 2003

The main goal of the Tera Watt A Cumulator project (Institute
for Theoretical and Experimental Physics, Moscow) is accumulation
in the storage ring of an intense ion beam, its longitudinal
compression and the use of the extracted beam for plasma
experiments. However, beam parameters at the target are decreased
because of extreme transverse heating and growth of the beam
momentum spread due to intrabeam scattering. These effects can
be suppressed by application of the electron cooling system
(ECS). Design study of ECS has been performed in the Joint
Institute for Nuclear Research. The design project and
characteristics of the system are described, as well as analysis
of the accumulation kinetics in the presence of the cooling
system. Design work has shown that because of the small length
of the straight section (2.35 m), the effective length of the
cooling system is small (about 55–60 cm). Nevertheless,
for long accumulation times (>100 s), the system allows us
to significantly improve the beam parameters at the target
(specific energy, specific power, and so on) and to suppress
the beam losses by an order of magnitude.
Heavy ion–plasma interaction of IFE concern: Where
do we stand now?
Authors: DEUTSCH CLAUDE , NERSYSIAN HRACHYA B. , CERECEDA CARLO
Published: February 2003

Two distinct issues of recent concern for ion–plasma
interactions are investigated. First, the subtle connection
between quantum and classical ion stopping is clarified by varying
the space dimension. Then we evaluate the range of thermonuclear
αS′ in dense plasmas simultaneously
magnetized and compressed.
Swift heavy ions in dense plasmas: The interaction process
as a probe of the plasma properties
Authors: MAYNARD GILLES
Published: February 2003

In this article, we analyze the sensitivity of the charge and
energy distribution of a swift heavy ion beam interacting with
a dense plasma on the thermodynamic and dynamic properties of
the target. We study more particularly partially ionized carbon
targets in which both the bound and the free electrons yield
a significant contribution to the stopping. The emphasis is
put on direct and indirect correlation between charge transfer
and stopping. We show that nonlinearities, appearing in the
interaction process for heavy ions, increase the dependency
of the stopping on the plasma properties, indicating that
diagnostics based on the analysis of the beam ions can provide
valuable information on the target properties.
Stopping power for strong beam–plasma coupling
Authors: GERICKE D.O.
Published: February 2003

A model for the stopping power for strong beam–plasma
coupling is presented. The model calculates the stopping power
through a T-matrix approach which correctly describes close
binary collisions. A velocity-dependent screening length is
used in the beam particle–plasma electron interaction
to include dynamic screening effects. The model has the correct
limiting behavior for low and high beam particle velocities
and agrees well with simulation data up to very high coupling
strengths. Compared to other theories, which include strong
correlations and/or dynamic screening only approximately,
a smaller energy loss has been found; this leads to a considerably
longer stopping range.
Charge-state distribution and energy loss of 3.2-MeV oxygen
ions in laser plasma produced from solid hydrogen
Authors: KOJIMA M. , MITOMO M. , SASAKI T. , HASEGAWA J. , OGAWA M.
Published: February 2003

The charge-state distribution and the energy loss of oxygen
ions in a laser-produced hydrogen plasma have been investigated
experimentally. The plasma target had a maximum electron density
of 5 × 1018 cm−3 and a maximum
electron temperature of 13 eV. The mean charge state of the oxygen
ions in the hydrogen plasma was measured to be 5.1, which was considerably
higher than that in hydrogen gas. The energy loss of oxygen ions in
the plasma of a density less than 1 × 1018
cm−3 in the plasma showed a large enhancement compared
with that in hydrogen gas. However, the energy loss in the plasma of a
density above 1 × 1018 cm−3 showed no
enhancement.
Methods of charge-state analysis of fast ions inside matter
based on their X-ray spectral distribution
Authors: ROSMEJ F.B. , MORE R. , ROSMEJ O.N. , WIESER J. , BORISENKO N. , SHEVELKO V.P. , GEIßEL M. , BLAZEVIC A. , JACOBY J. , DEWALD E. , ROTH M. , BRAMBRINK E. , WEYRICH K. , HOFFMANN D.H.H. , GOLUBEV A.A. , TURTIKOV V. , FERTMAN A. , SHARKOV B.YU. , FAENOV A.YA. , PIKUZ T.A. , MAGUNOV A.I. , SKOBELEV I.YU.
Published: February 2003

The X-ray spectral distribution of swift heavy Ti and Ni ions
(11 MeV/u) observed inside aerogels (ρ = 0.1
g/cm3) and dense solids (quartz, ρ = 2.23
g/cm3) indicates a strong presence of simultaneous
3–5 charge states with one K-hole. We show that the
theoretical analysis can be split into two tasks: first, the
treatment of complex autoionizing states together with the
originating spectral distribution, and, second, a charge-state
distribution model. Involving the generalized line profile function
theory, we discuss attempts to couple charge-state distributions.
Energy loss dynamics of intense heavy ion beams interacting
with solid targets
Authors: VARENTSOV D. , SPILLER P. , TAHIR N.A. , HOFFMANN D.H.H. , CONSTANTIN C. , DEWALD E. , JACOBY J. , LOMONOSOV I.V. , NEUNER U. , SHUTOV A. , WIESER J. , UDREA S. , BOCK R.
Published: February 2003

At the Gesellschaft für Schwerionenforschung (GSI, Darmstadt)
intense beams of energetic heavy ions have been used to generate
high-energy-density (HED) state in matter by impact on solid
targets. Recently, we have developed a new method by which we
use the same heavy ion beam that heats the target to provide
information about the physical state of the interior of the
target (Varentsov et al., 2001). This is accomplished
by measuring the energy loss dynamics (ELD) of the
beam emerging from the back surface of the target. For this
purpose, a new time-resolving energy loss spectrometer
(scintillating Bragg-peak (SBP) spectrometer) has been developed.
In our experiments we have measured energy loss dynamics of
intense beams of 238U, 86Kr, 40Ar,
and 18O ions during the interaction with solid rare-gas
targets, such as solid Ne and solid Xe. We observed continuous
reduction in the energy loss during the interaction time due
to rapid hydrodynamic response of the ion-beam-heated target
matter. These are the first measurements of this kind.
Two-dimensional hydrodynamic simulations were carried out using
the beam and target parameters of the experiments. The conducted
research has established that the ELD measurement technique
is an excellent diagnostic method for HED matter. It specifically
allows for direct and quantitative comparison with the results
of hydrodynamic simulations, providing experimental data for
verification of computer codes and underlying theoretical models.
The ELD measurements will be used as a standard diagnostics
in the future experiments on investigation of the HED matter
induced by intense heavy ion beams, such as the HI-HEX (Heavy
Ion Heating and EXpansion) EOS studies (Hoffmann et al.,
2002).
Charge-changing ion–ion collisions in heavy ion fusion
Authors: BRÄUNING H. , DIEHL A. , DIEMAR K.v. , THEIß A. , TRASSL R. , SALZBORN E. , HOFMANN I.
Published: February 2003

In heavy ion fusion, the compression of the DT pellet requires
high intensity beams of ions in the gigaelectron volt energy
range. Charge-changing collisions due to intrabeam scattering
can have a high impact on the design of adequate accelerator
and storage rings. Not only do intensity losses have to be taken
into account, but also the deposition of energy on the beam
lines after bending magnets, for example, may be nonnegligible.
The center-of-mass energy for these intrabeam collisions is
typically in the kiloelectron volt range for beam energies in
the order of several gigaelectron volts. In this article, we
present experimental cross sections for charge transfer and
ionization in homonuclear collisions of Ar4+,
Kr4+, and Xe4+, and for charge transfer
only in homonuclear collisions of Pb4+ and
Bi4+. Using a hypothetical 100-Tm synchrotron as
an example, expected particle losses are calculated based on
the experimental data. The results are compared with expectations
for singly charged Bi+ ions, which are usually
considered for heavy ion fusion.
Analytical and numerical studies of heavy ion beam transport
in the fusion chamber
Authors: KAGANOVICH IGOR D. , STARTSEV EDWARD A. , DAVIDSON RONALD C.
Published: February 2003

The propagation of a high-current finite-length ion charge
bunch through a background plasma is of interest for many
applications, including heavy ion fusion, plasma lenses, cosmic
ray propagation, and so forth. Charge neutralization has been
studied both analytically and numerically during ion beam entry,
propagation, and exit from the plasma. A suite of codes has
been developed for calculating the degree of charge and current
neutralization of the ion beam pulse by the background plasma.
The code suite consists of two different codes: a fully
electromagnetic, relativistic particle-in-cell code, and a
relativistic Darwin model for long beams. As a result of a number
of simplifications, the second code is hundreds of times faster
than the first one and can be used for most cases of practical
interest, while the first code provides important benchmarking
for the second. An analytical theory has been developed using
the assumption of long charge bunches and conservation of
generalized vorticity. The model predicts nearly complete charge
neutralization during quasi-steady-state propagation provided
the beam pulse duration τb is much longer
than the inverse electron plasma frequency
ωp−1, where
ωp = (4πnpe2/me)1/2
and np is the background plasma density.
In the opposite limit, the beam head excites large-amplitude
plasma waves. Similarly, the beam current is well neutralized
provided ωpτb >> 1
and the beam radius is much larger than plasma skin depth
δp = c/ωp.
Equivalently, the condition for current neutralization can be expressed
in terms of the beam current as Ib >>
4.25Zb βb(nb
/np)kA, where
nb is the beam density,
Zb is the ion charge, and
Vb = βbc
is the beam velocity; and the condition for charge neutralization
can be expressed as Ib >>
4.25βb3(nb
/np)(rb
/lb)2kA,
where lb and rb
are the beam length and radius, respectively. For long charge bunches, the
analytical results agree well with the results of numerical simulations. The
visualization of the data obtained in the numerical simulations
shows complex collective phenomena during beam entry into and
exit from the plasma.
Stability of gas discharge channels for final beam transport
Authors: TAUSCHWITZ A. , BIRKNER R. , KNOBLOCH R. , NEFF S. , NIEMANN C. , PENACHE D. , PRESURA R. , PONCE D. , YU S.
Published: February 2003

Discharge plasma channels have been investigated in recent
years at Gesellschaft für Schwerionenforschung–Darmstadt
(GSI) and at the Lawrence Berkeley National Laboratory in Berkeley,
California, in a number of experiments. A short summary of the
experimental work at Berkeley and GSI is given. Different
initiation mechanisms for gas discharges of up to 60 kA were
studied and compared. In the Berkeley experiments, laser ionization
of organic vapors in a buffer gas was used to initiate and direct
the discharge while at GSI, laser gas heating and ion-beam-induced
gas ionization were tested as initiation mechanisms. These three
initiation techniques are compared and the stability of the
resulting discharge channels is discussed. A discharge current
of 50 kA, a channel diameter well below 1 cm, a pointing stability
better than 200 μm, and MHD stability of more than 10 μs
have been demonstrated simultaneously in the recent experiments.
These parameters are sufficient or close to the requirements
of a reactor application depending on the details of the target
design. The experimental results show that transport channels
work with sufficient stability, reproducibility, and ion optical
properties for a wide pressure range of discharge gases and
pressures.
Induced radioactivity problem for high-power heavy ion
accelerators: Experimental investigation and long-time predictions
Authors: FERTMAN A. , BAKHMETJEV I. , BATYAEV V. , BORISENKO N. , CHERKASOV A. , GOLUBEV A. , KANTSYREV A. , KARPIKHIN E. , KOLDOBSKY A. , LIPATOV K. , MULAMBETOV R. , MULAMBETOVA S. , NEKRASOV YU. , PROKOURONOV M. , ROUDSKOY I. , SHARKOV B. , SMIRNOV G. , TITARENKO YU. , TURTIKOV V. , ZHIVUN V. , FEHRENBACHER G. , HASSE R.W. , HOFFMANN D.H.H. , HOFMANN I. , MUSTAFIN E. , WEYRICH K. , WIESER J. , MASHNIK S. , BARASHENKOV V. , GUDIMA K.
Published: February 2003

The experimental results of the activation spectra, dose rate
measurements, and the residual nuclide production cross sections
obtained after the irradiation of the NatCu and
59Co targets by 12C ion beams at ITEP and
GSI are presented in this paper. These results are compared with
simulations by the CASCADE and LAQGSM codes.
A credible pathway for heavy ion driven target fabrication
and injection
Authors: GOODIN D.T. , NOBILE A. , ALEXANDER N.B. , BROWN L.C. , MAXWELL J.L. , PULSIFER J. , SCHWENDT A.M. , TILLACK M. , WILLMS R.S.
Published: February 2003

The Target Fabrication Facility (TFF) of an inertial fusion
energy (IFE) power plant must supply about 500,000 targets per
day. The target is injected into the target chamber at a rate
of 5–10 Hz and tracked precisely so the heavy ion driver
beams can be directed to the target. The feasibility of developing
successful fabrication and injection methodologies at the low
cost required for energy production (about $0.25/target,
approximately 104 times less than current costs) is a
critical issue for inertial fusion energy. A significant program is
underway to develop the high-volume methods to supply economical IFE
targets. This article reviews the requirements for heavy ion driven
IFE target fabrication and injection, and presents the current status
of and results from the development program. For the first time,
an entire pathway from beginning to end is outlined for fabrication
of a high-gain, distributed radiator target. A significant
development and scale-up program will be necessary to implement
this pathway for mass production of IFE targets.
TOWARD TRANSPARENCY IN HEALTH TECHNOLOGY ASSESSMENT
Authors: Hailey David
Published: February 2003

Objectives: As an initiative of the International Network of Agencies for Health Technology Assessment (INAHTA), a checklist for assessment reports was developed as a means of improving transparency and consistency in HTA.

Methods: Preparation of a summary of key elements in HTA reports, drawing on experience in preparation of such documents, information from guidelines for HTA, and individual assessments. Review by INAHTA agencies and modification of the summary to reflect the consensus.

Results: The resulting checklist includes 17 questions, with supporting detail. General areas covered include preliminary information, why and how the assessment has been prepared, the results of the assessment, implications of the results, and conclusions.

Conclusions: The checklist is intended to be considered by those preparing or using an HTA report. It reflects the views of INAHTA members and is seen as a mechanism to improve the standard of HTA reports, being complementary to the more detailed guidelines on how to conduct assessments.
DOES CLINICAL TRIAL SUBJECT SELECTION RESTRICT THE ABILITY TO GENERALIZE USE AND COST OF HEALTH SERVICES TO “REAL LIFE” SUBJECTS?
Authors: Kennedy Wendy A. , Laurier Claudine , Malo Jean-Luc , Ghezzo Heberto , L'archevêque Jocelyne , Contandriopoulos André-Pierre
Published: February 2003

Objectives: To explore one aspect of the external validity of the randomized controlled trial (RCT), specifically how being selected for inclusion in a trial and having participated has influenced the use and cost of asthma-related health services.

Methods: Services used by asthmatic users of inhaled corticosteroids (iCSTs) having previously participated in an RCT (TS, n = 46) were compared with individuals who had never participated (NS, n = 51).

Results: TS were more likely to use higher (≥400 μg) daily doses of iCSTs than NS (OR, 3.3; 95% CI, 1.1–8.3) but less likely to visit emergency departments (OR, 0.3; 95% CI, 0.1–0.7). Total asthma-related costs did not differ significantly.

Conclusions: Subject differences may impede generalizing from RCTs to real life.
PRE-ASSESSMENT TO ASSESS THE MATCH BETWEEN COST-EFFECTIVENESS RESULTS AND DECISION MAKERS' INFORMATION NEEDS
Authors: IJzerman Maarten J. , Reuzel Robert P. B. , Severens Hans L.
Published: February 2003

Objective: To determine if a pre-assessment can be used to establish whether cost-effectiveness results would meet the actual information needs of Dutch healthcare decision makers.

Methods: Two recent studies in rehabilitation medicine served as study material. Based on Wholey, a limited pre-assessment was performed in which the potential impact of cost-effectiveness analysis (CEA) results on intended users' decision making was assessed. Desk research and semi-structured interviews with several intended users of CEA results were performed. These included general practitioners, representatives of health insurance companies, the Health Care Insurance Board (CvZ), and medical guidelines committees.

Results: In day-to-day decision making of the interviewed decision makers, a cost-effectiveness criterion seemed to be of limited importance. Instead, results from clinical effectiveness studies and budget impact studies appeared to be sufficient. CvZ, however, preferred relative cost-effectiveness to be a criterion for inclusion in future reimbursement guidelines. In both cases the limited pre-assessments changed the expectations of the investigators regarding decision-making impact of an economic evaluation.

Conclusion: This study revealed that the use of CEA results for Dutch micro- and meso-level healthcare decision making is not self-evident. The main purpose of CEA results is to support health policy making and planning at a macroeconomic level. Pre-assessment can be a valuable tool in designing a CEA to support the actual information needs of the decision makers.
CRUCIAL FACTORS THAT INFLUENCE COST-EFFECTIVENESS OF UNIVERSAL HEPATITIS B IMMUNIZATION IN INDIA
Authors: Prakash Charu
Published: February 2003

This study examines the parameters crucial to cost-effectiveness of universal hepatitis B immunization in India. An incremental cost-effectiveness analysis was done using a decision tree (Markov model) to follow up a hypothetical cohort of 100,000 newborns for the effects of hepatitis B acquired vertically at birth. The measure of effectiveness was disability-adjusted life-years gained. Uncertainty analysis and Scenario analysis were done using Latin hypercube sampling. Hepatitis B endemicity is the most important factor, followed by the cost of vaccine. Other factors of some influence are vaccination coverage, vaccine efficacy, HBeAg positivity, and vaccine wastage.
EFFICACY AND SAFETY OF VISCOSUPPLEMENTATION WITH HYLAN G-F 20 FOR THE TREATMENT OF KNEE OSTEOARTHRITIS
Authors: Espallargues Mireia , Pons Joan M. V.
Published: February 2003

Objectives: To review the scientific evidence on the efficacy, effectiveness, and safety of intra-articular injections of Hylan G-F 20 for the treatment of knee osteoarthritis.

Methods: Systematic review of experimental and observational studies performed in humans up to December 1999. Qualitative and quantitative (meta-analytic) techniques were used for data synthesis.

Results: A single course of intra-articular Hylan G{-}F 20 provides a statistically significant and clinically relevant short-term decrease of the painful symptomatology of knee osteoarthritis and improves joint function. It also seems to delay the need for knee replacement, if results observed in noncontrolled studies are confirmed. Hylan G-F 20 has a comparable efficacy to that of oral NSAID, and a smaller risk of gastrointestinal adverse effects. It seems to be well tolerated and safe, but the short follow-up in most studies limits any extrapolation of the effectiveness and safety over the longer term. There is also scarce evidence on the effect of multiple courses of Hylan G-F 20, and the scientific rigor of both experimental and nonexperimental studies reviewed is somewhat limited.

Conclusions: Whereas there is good quality scientific evidence showing that Hylan G-F 20 is a safe and well-tolerated therapy providing a short-term decrease of the pain symptoms while improving joint function, the delay of the need for knee replacement as well as the durability of the effect over the longer term have only been demonstrated in noncontrolled clinical series. The available evidence is not sufficient to reach firm conclusions on the effect of multiple courses of intra-articular injections of Hylan G-F 20 on health outcomes.
DEVELOPMENT OF EXPLICIT CRITERIA FOR TOTAL KNEE REPLACEMENT
Authors: Escobar Antonio , Quintana José Maria , Aróstegui Immaculada , Azkárate Jesús , Güenaga José Ignacio , Arenaza Juan Carlos , Garai Idoia
Published: February 2003

Objectives: To develop and test an appropriateness of indications tool for total knee replacement (TKR) in patients with osteoarthritis.

Methods: Criteria were developed using a modified Delphi panel judgment. Another panel rated the same indications, and the results were compared with the main panel. Test-retest of the main panel was performed. Regression models were used to assess the contribution of each algorithm variable. A classification tree was developed.

Results: The procedure was considered appropriate in 167 (26.8%) scenarios, and there was agreement on 112 (67.1%) of them. When the rates of the main panel were compared with those of a second panel, the result was a kappa statistic of 0.75. The test-retest kappa for the main panel was 0.78. Neither in the first case nor in the second was there an instance in which a scenario classified as appropriate shifted to inappropriate or vice versa. The regression models showed that symptomatology and radiology were the variables that explained most of the variability of appropriateness as determined by panelists. In the classification tree performed, the probability of misclassification was 3.8% with 150 scenarios, of the 156 analyzed and classified correctly.

Conclusions: The previous parameters tested showed acceptable results for an evaluation tool. These results support the use of this algorithm as an aid in formulating clinical practice guidelines and to promote the appropriateness of TKR.
A COST-EFFECTIVENESS ANALYSIS OF rhDNase IN CHILDREN WITH CYSTIC FIBROSIS
Authors: Grieve Richard , Thompson Simon , Normand Charles , Suri Ranjan , Bush Andrew , Wallis Colin
Published: February 2003

Objectives: This study compared the relative cost-effectiveness of daily recombinant human deoxyribonuclease (rhDNase), with alternate day rhDNase and hypertonic saline (HS) for treating children with cystic fibrosis (CF).

Methods: A randomized controlled trial with a crossover design allocated 40 CF children consecutively to 12 weeks of daily rhDNase, alternate day rhDNase, or HS. The primary outcome measure was forced expiratory volume in 1 second (FEV1), a measure of lung function. All health resource use was prospectively documented for each patient and multiplied by unit costs to give a total health service cost for each 12-week treatment period. The nonparametric bootstrap method was used to present cost-effectiveness acceptability curves and net benefit statistics for each treatment comparison, for various hypothetical levels of the decision maker's ceiling ratio.

Results: Compared with HS, there was a 14% improvement in FEV1 for daily rhDNase (95% CI, 5% to 23%), and a 12% improvement (95% CI, 2% to 22%) for alternate day rhDNase. For a ceiling ratio of £200 per 1% gain in FEV1, the mean net benefits of daily and alternate day rhDNase compared with HS were £1,158 (95% CI, −£621 to 2,842) and £1,188 (95% CI, −847 to 3,343), respectively; the mean net benefit of daily compared with alternate day rhDNase was *minus;£30 (95% CI, −£2,091 to 1,576).

Conclusions: If decision makers are prepared to pay £200 for a 1% gain in FEV1 over a 12-week period, then on average either rhDNase strategy is cost-effective.
COUNSELING VERSUS ANTIDEPRESSANT THERAPY FOR THE TREATMENT OF MILD TO MODERATE DEPRESSION IN PRIMARY CARE
Authors: Miller Paul , Chilvers Clair , Dewey Michael , Fielding Katherine , Gretton Virginia , Palmer Ben , Weller David , Churchill Richard , Williams Idris , Bedi Navjot , Duggan Conor , Lee Alan , Harrison Glynn
Published: February 2003

Objectives: To compare the cost-effectiveness of generic psychological therapy (counseling) with routinely prescribed antidepressant drugs in a naturalistic general practice setting for a follow-up period of 12 months.

Methods: Economic analysis alongside a randomized clinical trial with patient preference arm. Comparison of depression-related health service costs at 12 months. Cost-effectiveness analysis of bootstrapped trial data using net monetary benefits and acceptability curves.

Results: No significant difference between the mean observed costs of patients randomized to antidepressants or to counseling (£342 vs £302, p = .56 [t test]). If decision makers are not willing to pay more for additional benefits (value placed on extra patient with good outcome, denoted by K, is zero), then we find little difference between the treatment modalities in terms of cost-effectiveness. If decision makers do place value on additional benefit (K > £0), then the antidepressant group becomes more likely to be cost-effective. This likelihood is in excess of 90% where decision makers are prepared to pay an additional £2,000 or more per additional patient with a good global outcome. The mean values for incremental net monetary benefits (INMB) from antidepressants are substantial for higher values of K (INMB = £406 when K = £2,500).

Conclusions: For a small proportion of patients, the counseling intervention (as specified in this trial) is a dominant cost-effective strategy. For a larger proportion of patients, the antidepressant intervention (as specified in this trial) is the dominant cost-effective strategy. For the remaining group of patients, cost-effectiveness depends on the value of K. Since we cannot observe K, acceptability curves are a useful way to inform decision makers.
PRIORITIZING PATIENTS FOR ELECTIVE SURGERY
Authors: Derrett Sarah , Devlin Nancy , Hansen Paul , Herbison Peter
Published: February 2003

Objectives: Many hospitals in New Zealand have been using clinical priority assessment criteria (CPAC) to select and prioritize patients for access to publicly funded elective surgery. CPAC usually consist of clinical, patient-experienced, and social measures. The objective of this study was to determine how robust patient rankings were and the extent to which the patients selected were those who benefited the most from surgery.

Methods: Patients prioritized for cataract (n = 101), prostate (n = 103), and hip or knee joint replacement (n = 137) surgery according to CPAC were assessed using the EQ-5D, SF-12, and condition-related patient-experienced health status measures before and after treatment. Correlations between the rankings of patients on the CPACs and the alternative instruments were explored.

Results: For each surgery group, the CPAC ranking of patients was not strongly correlated with rankings obtained using their before-treatment EQ-5D (valued) profiles or the SF-12, although there was some correlation with rankings according to the condition-related measures. Improvements in the health status of patients who were operated on, as measured by the change in their EQ-5D values, were poorly correlated with equivalent changes on the SF-12 and condition-related measures. Patients' baseline health status according to the CPAC, the EQ-5D, and the SF-12 patient-experienced measures was only slightly related to the magnitude of benefit following surgery. The strongest predictors of improvement in health status were the baseline condition-related measures.

Conclusions: The current method of prioritizing patients in New Zealand requires reconsideration, although a gold standard method for prioritization is not immediately apparent from these results.
LONG-TERM IMPACT OF A RESTRICTIVE LABORATORY TEST ORDERING FORM ON TUMOR MARKER PRESCRIPTIONS
Authors: Durieux Pierre , Ravaud Philippe , Porcher Raphaél , Fulla Yvonne , Manet Catherine-Sophie , Chaussade Stanislas
Published: February 2003

Objective: To evaluate the long-term impact of an intervention designed to reduce the ordering of three tumor markers frequently prescribed for gastroenterologic diseases (carcinoembryonic antigen, alpha-fetoprotein, carbohydrate antigen 19-9).

Methods: A prospective study with time series analysis in a teaching hospital. Local clinical guidelines were developed and implemented through a new order form, designed as a reminder to the physician, restricting the ordering of laboratory tests. Ratios between the number of markers ordered and number of admissions were recorded during a 3-month period before and after intervention in the whole hospital and monthly on a 4-year period in two wards of the hospital (Department of Gastroenterology and Department of Internal Medicine). To evaluate the appropriateness of tumor marker orders, audits were performed on a sample of order forms, before and after (1 month and 2 years after) the implementation of the new order form.

Results: The analysis of covariance showed a significant effect of the intervention in the hospital (p < .01), and in the Departments of Gastroenterology (p < .01) and Internal Medicine (p < .007). The decrease of tumor marker orders ranged from 25% (Internal Medicine Department) to 55% (whole hospital). A similar decrease was observed for the three studied markers. The appropriateness of prescriptions increased from 54.6% before to 73.6% after the implementation of the new order form, but decreased to 52.9% 2 years after intervention.

Conclusions: Providing a reminder to clinicians through a specific order form represents an inexpensive and easy way to implement guidelines on use of laboratory tests.
THE VALUE OF THE MANAGED ENTRY OF NEW DRUGS
Authors: Payne Katherine , Davies Linda M. , Noyce Peter R. , Weiss Marjorie C.
Published: February 2003

Objective: A United Kingdom Department of Health directive (EL[94]72) asked Health Authorities to manage the entry of new drugs into practice. There seem to be costs associated with the decision-making process of managed entry, but no clear evidence of benefit to patient populations. The objective of this study was to assess the potential costs and outcomes of different models of managed entry, using the example of donepezil in the North West Health Region of the U.K. National Health Service. This is a preliminary study designed to identify the key pieces of information required to evaluate the value of managed entry.

Methods: Decision analytic models of three Health Authorities' approaches to manage the entry of donepezil were used to estimate the expected costs and effectiveness of the process. Resource use data were obtained from published sources and the relevant Health Authority. Probabilistic sensitivity analysis was used to determine the robustness of the results.

Results: The process of managed entry of donepezil was associated with higher expected costs and higher expected outcome than no managed entry. The 95% confidence intervals for the net expected costs and net expected outcomes were relatively narrow and did not cross zero, which suggests a statistical difference between managed entry and no managed entry for donepezil. The incremental cost-effectiveness ratios for managed entry of donepezil indicate that, compared with no managed entry, there were substantial differences between the different models used in the three study sites. The expected cost per unit of cognitive function gained was between £18,000 in study site 001 to £28,000 in study site 010. The expected cost per person with a clinically significant improvement was between £140,000 and £230,000. The expected cost per QALY ranged from £470,000 to £19.3 million.

Conclusions: Managed entry does not appear to be a worthwhile mechanism to introduce drugs into practice. However, poor accessibility and availability of data means that the results are highly uncertain. The lack of data presents serious obstacles for both researchers and policy makers wishing to develop evidence-based policy and practice.