96Sr run July 2007

 

Target issues:

* #355 UC2, MK8, CF4

* Sr and K mass markers

* HRS separator

* molecular beam 96Sr+19F

* Yield values:

            The experiment estimated ~1E4 Sr/s at Miniball

            No current measured with radioactive beam

            At the beginning 7E5 96Sr+19F/uC; in the end 1.3E5/uC

 

Experimental issues:

* Miniball

* IS451

 

 

REX issues:

breeding time, efficiency and currents:    

 

88Sr19F (stable):
HRS.FC490=93 pA            Trap inj plate=110         RFQ.FC20(23+)=50        
Tbreed=120 ms, cw injection into EBIS, Icoll=216 mA, optimised for 23+
Efficiency(Trap+BTS+EBIS+sep, 23+)=1.9%

normal extraction

 

96Sr19F (radioactive):

25+       beam jumping from 0-90 pA on trap inj plate, 2 to 10 pA on RFQ.FC20, XL65.FC40=1-5 pA (mostly 115In and 115Ag)

27+       0-0.5pA on RFQ.FC20 (also with trap inj plate in, so probably stable background)

normal extraction

23+ most/part (?) of the run was carried out with this charge state

 

linac transmission and energy:

            20Ne5+             Aq 4                 2.86MeV/u        70%

            88Sr23+            Aq 3.826           2.87MeV/u        67%

            88Sr21+            Aq 4.190           2.86MeV/u        70%

 

 

Technical problems:

* Could not run 96Sr25+ and 96Sr26+ due to 115In contamination (30+ and 31+). Should have checked beforehand for the presence of stable from Isolde at mass 96+19.

* 7GP2 and 3 tuners were not moving. Adjusted by hand after each scaling.

* IHS breaks down above 60kW.

* Poor transmission between 9GP and BEN.FC100 at 9GP energy. Need time to find a better tuning.

* At the end of the run attempted Sr98. No beta-decay count at Miniball

 

Comments and lessons learned

* 9GP at 90kW (500us 8-30Hz) during entire run without problems.

* Can run the low energy part with HRS beam in cw mode