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

REX issues

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+; BEN.FC100=5 pA

BEN.FC100=10-12 pA (with 2E13 p/p)

efficiency:

* HRS.FC490 to REXTRAP: 95% (checked with 132Xe beam)

* 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 TOF when injecting 84Kr. Earlier test with 78Kr had 33% total efficiency with 50% in Ne => 17%

* 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 PLC for the Linac vacuum was down and the programme had to be reloaded. Poor vacuum. One night of pumping.

lessons learned:

* Fredrik and Pierre can go to a conference