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:

Thu Nov 22 11:53:08 2018

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The target ladder is set for position 7 - the double alpha source.

Looking at the FAIR DAQ, for the Far S2 the first RAL amplifier (XV) shows:

<ul>
	<li>Alphas at channel 700</li>
	<li>Pulser centroid at channel ~2640, with 9 channel FWHM -&gt; corresponds to 44 keV FWHM at 4.91 keV/channel</li>
</ul>

The close S2 shows:

<ul>
	<li>Alphas at channel 700</li>
	<li>Same pulser centroid as far S2, with 6 channel FWHM -&gt; corrsponds to 24 keV FWHM at 4.91 keV/channel</li>
</ul>

We reenabled the top ICU box channels 0 and 5 (disabled during Feb 2018 shift)

We started an alpha-source run using the 241Am and 239Pu source, type: EA X, product number: 111109-1242002. Photo of source storage case is attached.

Alpha activity at 25/03/2010: 8.153 kBq

&nbsp;

We found the following strange behaviour

With DAQ list mode OFF:

<ul>
	<li>Trigger rate ~2300 - 2700/s</li>
	<li>Event mult ~ 140</li>
	<li>DT~18%</li>
</ul>

With DAQ list mode ON:

<ul>
	<li>Trigger rate ~300 - 900/s</li>
	<li>Event mult ~140</li>
	<li>DT ~ 70 - 90%</li>
</ul>

Currently ADC 2, 3, 4, and 5 are in use by the far and near S2&#39;s. ADC 6 and TDC 7 are not currently in use (we will need ADC 6 for the pin diode)

We set the lower threshold for ADC6 and TDC7 to 2046 out of 2047 channels - effectively disabling the two.

Now with list mode ON:

<ul>
	<li>Trigger rate ~ 1500 - 1700 /s</li>
	<li>Event mult ~ 65 - 70</li>
	<li>DT ~ 30 - 50 %</li>
</ul>

We restarted the DAQ machine

We started an alpha source run:

<ul>
	<li>Run number: 181122123034</li>
	<li>DT ~ 7 - 19%</li>
	<li>Trigger rate ~ 700 - 1000/s</li>
	<li>Event mult ~ 63</li>
</ul>

The PB-4 Pulser Settings are:

<ul>
	<li>Frequency: 250 Hz</li>
	<li>Delay: 1 us</li>
	<li>Rise Time: 0.1 us</li>
	<li>Fall Time: 100 us</li>
	<li>Reference: INT</li>
	<li>Polarity: +ve</li>
	<li>Amplitude on scope: 260mV</li>
	<li>Attenuation: X10 (X10 switch up, X2, X5, and the other X10 switch are down)</li>
</ul>

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AlphaSourceCertificate.jpg Original size: 2730x2955

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