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 Apr 12 14:14:09 2018

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Date: 06/04/2018

Before starting this beam test we lowered the channel thresholds on ADC 3 and 4 (modules 4 and 5) from 40 to 8

The diode Ortec 571 settings are:

<ul>
	<li>Fine gain = MAX</li>
	<li>Course gain = 200</li>
	<li>Shaping Time = 0.5us</li>
</ul>

The diode Delay Amp 1457 settings are:

<ul>
	<li>Delay = 1us</li>
	<li>Polarity = POS</li>
	<li>Range = 10V</li>
</ul>

The diode quad CFD (channel 4) threshold = 196 mV

The PB-5 Pulse Generator settings are:

<ul>
	<li>Fall Time = 100us</li>
	<li>Rate = 10Hz</li>
	<li>Delay = 250 ns</li>
	<li>Ampl = 1V</li>
	<li>Pol = POS</li>
	<li>Pulse Top = Tail</li>
	<li>Atten = 1X</li>
	<li>Clamp = OFF</li>
</ul>

(Make sure PB-5 = ON to output pulses)

At 19:14 we started the DAQ for 5.0 MeV 7Be at charge state 2+ on target CH2 III

<ul>
	<li>Dead time = 5%</li>
	<li>Trigger rate ~ 1.8kHz</li>
	<li>Event mult ~ 22.1</li>
	<li>Save name = RData_1/180406181929</li>
</ul>

At 19:30 we stopped the DAQ, Real time = 00:15:53, dead time = 5%, # good events = 1936195

See attached images for an example back strip and front strip of the central S2, and also for the diode spectrum

Before finishing for the day we decided to once again try to incorporate the downstream S2 into the DAQ setup, because this should have better angular resolution than the central S2

We opened the downstream iris (actuator setting = 1.5mm)

We plugged in RAL I, II, XI, and IV into ADC 1 (module 2) channels 0 -&gt;31, these are the first 32 channels of the downstream S2 preamp output

Even with no beam the DAQ DT = 92% with event mult = 52.0 --&gt; still have a noise problem with the downstream S2

At 19:41 the pressures read:

The detector biases were:

<ul>
	<li>Central S2 bias = -129.9V, leak I = 18.39 uA</li>
	<li>diode bias = -70.1V, leak I = 0.00uA</li>
	<li>Downstream S2 bias = -130.1V, leak I = 2.78uA</li>
</ul>

We called it a day and at 19:45 the detectors were switched off and the line valve closed for the night

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