=?ascii?B?W1NQQU1dICBTdGF0dXMgcmVwb3J0?= =?ascii?B?IGFuZCBjdXJyZW4gcXVlc3Rpb25z?= =?ascii?B?Lg==?=

["A. Vassiliev" <vassilie@mail.pnpi.spb.ru>]

Dear Colleagues,

I hope everybody had a good rest during a long-long holidays.

PNPI status.

1. The design of the "separation H/D device" is finalized.
Calculations of the separation degree has been done for real
dimensions and we are "satisfied" in a battle between technical
possibilities and "good wishes of separation specialists".
On base of bigger cooling power (20W at 20K) we increase the diameter
of the separation tube (now it is 25x1 - inner 23 mm). This give us a
possibility to use complete cooling power without "liquid hydrogen
corks" in the tube.
2. Vacuum an gas components ordered by Claude are in our hands.
3. All rough metal material (SS, Cu, Ag) are prepared.
4. Today about 30% of elements are ready.

So we do not any reasons for plans corrections.

Plans.
- Up to the middle of February - production and assembling.
- February - vacuum tests.
- Last week of February - packing.
- First week of March - delivery to PSI.

Work in PSI.

3 weeks in March - 1st week of April - 4 persons (Vasilyev A, Kravtsov
P., Vznuzdaev M. and one person from Alekseev's laboratory. All we
need Swiss visa).

- 2nd week of March - assembling in PSI and vacuum tests. Cleaning.
- 3d  week of March - cryogenic tests, software.
- 4th week of March - 1st week of April - hydrogen purification.

We do not have now common opinion where is better to make assembling
and first tests - near the target or in another place.

Project of necessary infrastructure in PSI and "components topography"
will be send to Claude one week later.

Tuning of the system.

On-line control.
First we have to be sure that separation column is working. For this
we are going to use QMS. If we assume that the initial deuterium
concentration is 3 ppm the concentration in purging gas from very
beginning will be 300-500 ppm (new calculations). It means that if we
create in the QMS volume pressure of hydrogen 10-4 mbar pressure of
the deuterium will be 3x10-8 - 5x10-8 mbar. This value has to be
visible by QMS. If we will use QMS as a leak detector on the mass 4
(deuterium) we will get the dependance of the deuterium concentration
from the time. By the fine valve we can organize "the comfortable"
conditions for QMS.
Of-line control.
We will collect ALL purging gas for later analyses in the sample. If we will purify
500 l of hydrogen with D2 concentration 3 ppm in 50 l of purging gas
will be 30 ppm of deuterium.

What we need for QMS analyses?
We need QMS with pumping system. We have in CHUPS system QMS+Turbo. If
we will use this assembly for the analyses purposes we need one MORE
pumping system for CHUPS and separation column. If Claude will not
find possibility to find pumping system on ONE month in PSI I can try
to find this one in Juelich.

Up to now we did not finalize the procedure of purifications. I can
not say NOW how much hydrogen we need for work (including tests) and
wat vessels we will use. This one we will discuss with Claude later (but in January).

Missing components....

For the system we need 3 cryo PT100 (+1 reserve). Claude "borrowed" 4 these sensors
for CHUPS in cryogenic group.
We need PT-102 or PT-103 from Lakeshore (PT-102 cheaper 75$ per one)
www.lakeshore.com/temp/sen
This is Swiss firm.

We need two differential pressure transmitters by Dwyer. Series 631.
Price 450$ per one plus 20$ cable.
we need 0.5" w.c. sensor with 500 psi static pressure and
          5" w.c. Firs one we need for the measurements of the liquid
          hydrogen level in the bottom of the system, the second one
          for the control of the pressure drop in the column,
          including of the "emergency" situation when the liquid from
          the top close the gas flux from the bottom.
www.dwyer-inst.com/htdocs/pressure
Series 631.
This is US firm.


With best regards   Sasha.










-- 
Best regards,
 A.                            mailto:vassilie@mail.pnpi.spb.ru