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Dear Colleagues,
Here is a summary of discussions at
PNPI on the status of developments of the gas circulation and
deplition systems:
1. Gas circulating system. (GCS)
The work is going on. Most of
mechanical parts are produced. Some components still missing
(to be purchased via CRDF) that
makes some delay in the project. The plan is to complete GCS
in May. Tests of GCS will require
depleted protium gas ( on a level of 20 ppm of D or
less).
To have this gas we
need:
Depleted protium water ( at least 5 Liters) and
Gas generator system.
The gas generator system has been sent
right now from PSI. But it is polluted with the 2000ppm Canadian
gas.
Our people will try to clean it up
as much as possible.
The depleted water could be
bought in Canada . Another option is to produce such water at PNPI as considered
below.
2. 5-10 ppm depleted water production
at PNPI.
Our colleagues
from Neutron Lab at PNPI agreed to
start to work on production of the depleted water
using their old
distillation exchange columns .
This is a closed loop with water
heating at the bottom and vapour cooling in the upper part of the
column.
The efficiency is not so
high that requires long columns. The length of the available columns is 10
meters.
Starting from the natural
water,such column can produce 5-10 ppm depleted water after at least one
month
of continious
operation.The initial filling requires 40 liters of the water, and
the amount of the depleted water
produced after such cycle
is 10 liters.
They have 4 such columns
which,however, should be reanimated . The
columns will work in parallel to provide the
required amount of water in two months.We promised to pay
salaries for the people operating these columns and
to buy
some materials. The plan is to produce 8-9 liters of
depleted water (5-10 ppm of D) by mid of
May.
This water can be used for
testing the GCS and ,possibly, for production of sub-ppm depleted water for our
experiment.
3. Sub-ppm depleted water production at
PNPI
Same columns filled initially
with 5-10 ppm depleted water should provide higher depletion (1ppm or
better)
that should be
,however,demonstrated experimentally. For this purpose, one of the column will
be transferred
to this mode while the other three columns will continue to accumulate
the 10 ppm water. Note that initial filling of one
column requires 40 liters of
water.(better 50 L)
4. Developement of a new depletion
method.
The principle of the method was
reported at the MuCAP meeting at PSI in November.
It uses a much more
efficient exchange process (H2O-water -- H2 gas in presence of a
catalyser).
The length of the column
will be shorter and the production rate higher ( 15 liters
of 1ppm depleted
water or equivalent amount of H2-gas per month).
Another advantage of this
method: it can be implemented in our set up to clean up periodically
our gas
from deuterium. Note
that this would require considerable amount of 1ppm depleted water (2
liters per one purification
cycle) which, hopefully, can be produced at PNPI by one of the
described above methods.
Developement of this
method will require some investments :
Electrolyser (
H2O-water-- to H2 gas) ,H2 burning element ( H2-gas---to H2O-water)
,some mechanical structure etc.
The electrolyser is
available at the lab.
We decided to cover
all the costs except the H2 burning element which we believe could
be supplied by our US
colleagues as it was
discussed at the PSI meeting.
As concerns
the time scale,in principlle, one can expect some results by the end of
this year.
5. Precision analysis
of d-concentration.
Our colleagues
from Neutron lab. are planning to improve the sensibility of their
measuring device
(IR
spectrophotometer) up to 1 ppm level
by implementing an additional element
(Multipass gas cell)
This element
can be supplied by a Russian
company, and we agreed to cover the
cost.
Hopefully,
this work can be done within three months.
Also, we shall
continue cooperation with Ioffe institute in the D2- analysis by the mass-
spectrometer.
With best regards Alexey
Right now I have received a message from PNPI. The
first column started operation !!!
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