AIDA
GELINA
BRIKEN
nToF
CRIB
ISOLDE
CIRCE
nTOFCapture
DESPEC
DTAS
EDI_PSA
179Ta
CARME
StellarModelling
DCF
K40
CARME
Draft saved at 00:00:00
Fields marked with
*
are required
Entry time:
Thu Apr 3 19:29:18 2025
Author
*
:
Subject
*
:
<p>Ion beam energy is calculated using Beamcalc (https://web-docs.gsi.de/~lestinsk/beamcalc/electron.php)</p> <p>Electron current is set to 4.3 mA and can be taken from Grafana</p> <p>Alpha factor is 50</p> <p>Ion energy is then adjusted using the cooler voltage</p> <p>The cooler voltage inserted into BeamCalc is taken from the FC20 voltage divider. However an offset from the space charge correction is required!</p> <p>This correction is determined experimentally by changing the electron current and finding the cooler voltage which maintains the optimum cooling of the beam.</p> <p>Attachment 1 shows this plot for 15N1+ at ~0.426 MeV/u</p> <p>Attachment 2 shows this same plot in comparison with BeamCalc</p> <p>To obtain the correct energy we need to subtract 2V from the voltage used in BeamCalc</p> <p>An example is shown in attachment 3</p> <p>Here to obtain an ion energy of 426.6 keV/u requires a cooler voltage of 246.7 V. But, due to the space charge correction this value should be 244.7 V.</p> <p>The cooler voltage setpoint should therefore be chosen so that the FC20 voltage divider reads 244.7 V.</p> <p>The setpoint needs to be ~0.55 V higher than the desired value i.e setpoint of 245.25 V to obtain the required 244.7 V (at least this beamtime it does)</p> <p> </p>
Encoding
:
HTML
ELCode
plain
Suppress Email notification
Attachment 1:
Drop attachments here...
Draft saved at 00:00:00
ELOG V3.1.4-unknown