Removal of 212Pb with distillation technique

1
Removal of 212Pb with distillation technique

• distillation of MO and PC
• Purification meeting, California
• Y.Kibe (Tohoku Univ.)

2
Contents

• Review of past results
• Motivation
• Experimental procedure
• Results of distillation
• Summary
• Next plans

3
Review of past results
Cycle No.
1st
2nd
3rd
(1.9 /- 1.4) x 10-4
(1.4 /- 0.6) x 10-3
(1.1 /- 0.8) x 10-4
MO
PC
(5.1 /- 0.7) x 10-3
(9.8 /- 3.2) x 10-4
MO PC
Last collaboration meeting, I showed the
reduction rate of dodecane has discrepancy
between each trial.
4
Motivation for experiments

• What is the discrepancy of reduction rate caused
  by ?
• We did not know the reason why reduction rate of
  MOPC is worse than that of MO.
• I distilled PC only and got the reduction rate.
• We did not get the record with test bench.
• I distilled MO in 5 cycles.

5
Candidate of the origin of discrepancy
(1), procedure itself
I fixed the experimental procedure and some
parameters.
(2), effect of heating
I distilled MO with setting the heating time to
60 min.
6
Experimental procedure (1)
Pressure 37 hPa Heater volume 80
1
2
3
Wait for 15min
1
Discard the sample for 5min. (5min sample)
2
Collect the sample for 5min. (normal sample)
3
7
Experimental procedure (2)
Pressure 37 hPa Heater volume 80
1
2
3
Wait for 15min
1
Discard the sample for 5min. (5min sample)
2
Wait for 40min and then collect the sample
(15540 60 min sample)
3
8
Results(1) (MO)
10-3
10-4
11/16
11/2
9
Results(2) (MO)
10-3
10-4
11/24
11/30
10
Results(3) (MO)
10-3
10-4
10/20
12/14
11
Results (PC)
10-2
10-3
10-4
12/8
12/21
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Summary of results

• With discarding the sample for 5min firstly, we
  got the reduction rate stably.
• The reduction rate of PC is better than that of
  MOPC.
• PC does not make the reduction rate of MOPC
  worse.
• We confirmed the reduction rate is getting better
  when we distill in many cycles.

13
Next plans

• We will distill MOPC according to appropriate
  procedure.
• It is difficult to decide the point where we
  should discard the sample.
• We did not try to distill PC in many cycles, so
  we will try.