ELOG CIRCE

AIDA GELINA BRIKEN nToF CRIB ISOLDE CIRCE nTOFCapture DESPEC DTAS EDI_PSA 179Ta CARME StellarModelling DCF K40

CIRCE

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Entry time:

Mon Dec 3 11:54:55 2018

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On 25/11/2018:

At 8:45 the pressures read (mBar):

<ul>
	<li>TPU1 = 1.0e-6</li>
	<li>TPU2 = 3.2e-7</li>
	<li>TPD1 = 6.5e-7</li>
	<li>TPD2 = 6.1e-7</li>
	<li>CHUP = Sensor Off</li>
	<li>CHDW = No Sensor</li>
</ul>

Biased detectors: Far S2 bias = -130.0V, leak I = 1.80uA. Diode bias = -70.1V, leak I = 0.00uA.

Checked pulser frequency:

<ul>
	<li>Frequency setting = 25Hz (250Hz max fine gain setting)</li>
	<li>Pulser frequency measured internally by scope: 19.29-&gt;19.31Hz</li>
	<li>Pulser frequency measured using cursors on scope: 19.38Hz</li>
</ul>

Target ladder left in position #2 overnight - 10mm aperture. Far S2 iris also left open overnight.

Checked for beam induced background from beam scattering on aluminium target frame and/or ladder. FC4 ~ 17pA, FCC ~ 6pA

Run # 181125090005

<ul>
	<li>Run time: 977s</li>
	<li>Pulser ON, as before</li>
	<li>Target: 10mm aperture</li>
	<li>Beam: 4.0MeV 7Be 2+</li>
</ul>

Tuned beam for 6.0MeV 7Li 2+

After tuning: FC4 = 1.05nA. Using 10mm aperture FCC = 520pA, using 3mm aperture FCC = 460-480pA.

Collected 7Li + p data using old target CH2 XVI (used for 7Be yesterday)

Run # 181125112005

<ul>
	<li>Run time: 754s</li>
	<li>Pulser ON, as before</li>
	<li>Target: CH2 XVI</li>
	<li>Beam: 6.0MeV 7Li 2+</li>
	<li>DT ~ 10%</li>
</ul>

Run # 181125113257

<ul>
	<li>Run time: 18s</li>
	<li>Pulser ON, as before</li>
	<li>Target: CH2 XVI</li>
	<li>Beam: 6.0MeV 7Li 2+</li>
</ul>

Moved target ladder to position # 4 - fresh CH2 XVIII

Run # 181125113734

<ul>
	<li>Run time: 324s</li>
	<li>Pulser ON, as before</li>
	<li>Target: CH2 XVIII</li>
	<li>Beam: 6.0MeV 7Li 2+</li>
</ul>

See attached picture 1 for a sample spectrum from one of the Far S2 front strips. See attached picture 2 for the diode spectrum.

Moved target ladder to position #5 - natC III

Run # 181125114513

<ul>
	<li>Run time: 620s</li>
	<li>Pulser ON, as before</li>
	<li>Target: natC III</li>
	<li>Beam: 6.0MeV 7Li 2+</li>
</ul>

After the previous run, it was discovered the pulser was still being split between the far S2 preamp test input, and the oscilloscope (morning check of pulser frequency). Therefore the pulser had an additional load and we expect a shift in the pulser amplitude compared to runs made yesterday.

Checking for beam induced background, the target ladder was moved to position #2 - blank 10mm aperture

Run # 181125115810

<ul>
	<li>Run time: 386s</li>
	<li>Pulser ON, as before</li>
	<li>Target: Blank 10mm aluminium frame</li>
	<li>DT ~ 8%</li>
	<li>FCC ~ 400pA</li>
</ul>

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Attachment 1:

181125113734_ADC1_Ch9.png Original size: 756x435

Attachment 2:

181125113734_ADC3_Ch16.png Original size: 756x435

Attachment 3:

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