Cu run August 2006
Target issues
* UC2-C #333, Ta surface, laser ionization
* mass markers K and Cu
* separator setup at 30.2 kV
* Yield check
Tape station broken so no yields
checks
According to Miniball
100 times better yield than last year
Target heated to 600 A
With 3 pulses, 3E13 p/p we measure 12 pA on the trap inj
plate with lasers on at mass 69. With lasers off 2-3 pA on the same plate. Thus, less than 25% Ga in the beam
For 73Cu, from coulomb excitation data: 73Cu/total=26%
REX issues
Isotopes accelerated: radioactive
71Cu20+, 69Cu20+, 67Cu19+, 73Cu19+
breeding times 68 ms for 19+ and 98 ms for 20+ (the latter
not optimum)
period time 100 ms for 71,69 and 67
period time 60 ms for 73
Currents:
71Cu20+ 4
pA on the trap inj plate in
the peak; BTS.FC20 2.5 pA in the peak;
RFQ.FC20 7 pA of 20+; 5 pA on
69Cu20+ On
BTS.FC20=3-3.5 pA,
RFQ.FC20=10.5 pA,
67Cu19+ With
3/14 pulses, 2E13 p/p we have:
5 pA on trap inj plate
2.5 pA on BTS.FC20 in the peak (50% eff), 100 ms period time
12 pA on RFQ.FC20 in the peak (25% eff), 68 ms breeding time
9 pA on
73Cu19+ With 5/14 pulses, 3E13 p/p (all peak values)
3.7 pA on trap inj plate
2 pA on BTS.FC20, 70 ms period time
3.6 pA RFQ.FC20, 68 ms breeding time
2.4 pA on
Efficiencies:
With 39K
For 20 ms period time, 5 ms beam gate, 14 ms breeding
time
Trap inj plate=145 pA,
BTS.FC20=71 pA => trap eff
49%
RFQ.FC20(10+)=153 pA => EBIS eff
21.5%
Total efficiency (trap+BTS+EBIS+sep)=10.6%
For 20 ms period time, 1 ms beam gate, 14 ms breeding time
Trap inj plate=26 pA,
BTS.FC20=15.5 pA => trap eff
60%
RFQ.FC20(10+)=39,5 pA => EBIS eff
25.5%
Total efficiency (trap+BTS+EBIS+sep)=15.2%
With 65Cu
With 1 ms beam gate, 100 ms period time, 68 ms
breeding time (optimised for 19+)
TRAP efficiency 50% (inj
plate = 26pA, BTS.FC20 = 13pA)
EBIS efficiency 22% (RFQ.FC20 = 55 pA for 19+)
Trap+EBIS+sep eff = 11.1%
With 1 ms beam gate, 100 ms period time, 98 ms
breeding time (non-optimum for 20+)
Trap inj plate=29 pA and RFQ.FC20(20+)=45 pA => Trap+EBIS+sep eff = 7.8%
REX low energy stage tuned
with 65Cu20+
5.8% total eff with 68 ms
breeding time
7.8% total eff with 98 ms breeding time
LINAC: Energy for A/q=3.55 2.95 MeV/u;
transmission 73%
Energy
for A/q=3.45 2.97
MeV/u; transmission 80%
Energy for A/q=3.526 2.99 MeV/u; transmission 75%
Energy
for A/q=3.842 2.88 MeV/u; transmission ~70%
technical problems:
* Lost settings for
* Insulation in the
capacitor in the anode tube for the 9-gap broken before the run
* EBIS cathode only
producing 165 mA even with an excessive cathode
heating
(slowly
recuperating during the run)
* Tape station not
operational. Trap inj plate used for proton scan.
* Forced ‘Missing patch
update’ for Windows machines in the middle of the run.
* BD watchdog programme stopped working after the Windows patch
installation
lessons:
* if
going to a blind mass, scale the complete machine; do not adjust the power
level of the 9-gap amplifier
* watch out that the values
in the Mass calibration Excel sheet have been written over