[Neutron] about SNIM-2

[V.Nietz]

Dear colleagues!
I address to the neutron community for help, first of all, to those who
investigate magnetic properties
of substance by neutron scattering using magnetic field.
In Frank Laboratory of Neutron Physics (Joint Institute for Nuclear
Research, Dubna, Russia)
there is the Spectrometer for Neutron Studies of Condensed Matter with a
Pulsed Magnetic Field (SNIM-2)
(Spectrometer consists of Neutron spectrometer NS-3 and a Pulsed magnetic
facility IMU-2;
the basic parameters of SNIM-2 you can see in ref. [1]: Nietz V.V.
"Prospects for the Use of the Pulsed
Fields in Neutron Research of Condensed Matter", Journal of Magnetism and
Magnetic
Materials, 2003, vol.260, pp.84-104.).
A few years ago the use of SNIM-2 was stopped and the installation was
preserved.
The basic reasons were the absence of the important element of SNIM-2 - the
pulsed magnets,
and absence of money for further development and manufacturing of them.
However, the spectrometer, except for magnets, is up to now in working
order,
i.e. is suitable for measurements of diffraction and inelastic neutron
scattering with a magnetic field.
Now in the world there is only one working pulsed magnetic installation - on
diffractometer used
with spallation source in КЕК, Japan. However, on this installation a flow
of thermal neutrons in a pulse
is two orders less, than on the SNIM-2 (see [1]). (Such information, which
the Japanese receive in a year,
we received for seven - ten days of measuring time on the SNIM-2.)
Besides, the power of Japanese magnetic installation is five - six times
less, than the IMU-2;
on this parameter we used only 15-20 % of opportunities of the IMU-2. As for
characteristics and
opportunities of physical researches, the SNIM-2 is a unique facility.
Now the situation has changed. In National High Magnetic Field Laboratory
(NHMFL), USA,
magnets necessary for us (250-300 kOe, 2 Hz, time of life ~10^7 pulses) are
developed and
their manufacturing is mastered. Now on the NHMFL initiative, the documents
are drawn
for financing from the fund CRDF (U.S. Civilian Research and Development
Foundation),
assigned for payment of delivery from NHMFL of pulsed magnets for the
SNIM-2,
and for preparation and realization of measurements with pulsed field on the
SNIM-2.
Besides, the pulsed magnets (up to 150-200 kOe) for diffraction researches
on the SNIM-2
are developed in Research Center for Materials Science at Extreme Conditions
(KYOKUGEN), Japan.
These magnets will be delivered to our Laboratory free-of-charge, for
fulfilment of the first experiments
in collaboration with Japanese colleagues.
Taking into account the unique opportunities of the IBR-2 reactor in
researches of condensed matter
in magnetic fields, which are practically unattainable for experiments on
other sources of neutrons,
and considering that now real conditions for fulfilment of such researches
on the SNIM-2 are created,
it would not be correct to stop this direction.
However, the creation of real conditions for continuation of the SNIM-2
operation made more active
the opponents of researches with a pulsed field on the IBR-2. In particular,
some of them want to liquidate the SNIM-2.
Please, send me your opinions on this question. I shall use them in my
actions.
To receive more detailed information write to me, nietz at nf.jinr.ru
October, 2003                                           V.V.Nietz