Kr run autumn
2005
Target issues:
* Target number #311. UCx, Mk7
* First
Ar95%/Xe5% mixture, then Kr/Ar/Xe/Ne/He
mixture for the setup
* Proton scan for 90Kr saved in ..iso/isotape/UC/311/90kr1.csv
* Ran at (270E10) or 600E10 protons per pulse for 88Kr and
2E13 p/p for 92Kr
isotopes
run: 88Kr21+ and 92Kr22+
breeding
time: 70 ms for 21+ and 98 ms for 22+
currents:
* For 12/12 pulses, 1.1E13 p/p with 88Kr we had:
TRAP inj
plate = 100 pA; BTS.FC20 = 22 pA
(incl Ne etc); RFQ.FC20 38 pA for 21+;
* For 12/12 pulses, 1.1E13 p/p with 92Kr we had:
TRAP inj plate = 20-40 pA; BTS.FC20 = 15 pA (incl Ne etc); RFQ.FC20 8-9 pA for 21+;
efficiency:
*
* Trap: 52% efficiency for stable 132Xe
(10 ms beam gate for 9.5 Hz);
Trap: 17% for stable 84Kr (2 ms beam gate, 90
pA on inj plate);
(the large Ne peak is substracted)
Trap: 15% for radioactive 88Kr (open beam
gate);
(We did not recheck the Ne
fraction. We saw with 84Kr the fraction depended on the amount of Kr. This may
explain the higher EBIS efficiency for 88Kr.)
Trap: ~25% (very uncertain) for radioactive
92Kr (open beam gate);
(two large peaks at lighter masses with ~50% of the current)
*
EBIS: 10.5% for 84Kr20+ (90 ms breeding time)
EBIS: 12.5% for 88Kr21+ (70 ms breeding time,
no beam gate)
EBIS: ~5% (very uncertain) for 92Kr22+ (98 ms breeding time, no beam
gate)
* Total Trap+EBIS efficiency 1.8% for 88Kr21+
* Total Trap+EBIS efficiency 1.3% for 92Kr22+
* Linac transmission: 76% for 88Kr21+
Linac
energy:
* 2.19 MeV/u
comments:
* The trap gives 1/3 of Ne in the
* Running with 9.5 Hz even with 70 ms breeding time. (At set
up time we thought the 9-gap would be needed, but they did not need it at the
last minute.)
* Limitation in 88Kr intensity was given by RP.
Doserate ~ 400 microSv/h
at contact of the trap roughing pump and PAXY11 stable at 12 microSv/h at 50 cm away from the pump for 1.1E13 12/12
protons and 88Kr.
After the trap, at the EBIS-BTS bellow and at the mass
separator slit ~100 uSv/.
technical problems:
* Siemens
lessons
learned:
* Fredrik and Pierre can go to a
conference