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Preparation for tuning
NMRs CONTROL (under development)
Two digital oscilloscopes are dedicated to NMR readout – one for the analysis line NMRs and one for the spectrograph NMRs
The scopes are located __ and are isolated from clean ground because this signals from the NMR probes are on a dirty ground
TURNING S800 MAGNETS ON/OFF (under development)
The powering of the S800 magnets needs to follow three steps:
Arming of Dump Switch The power supply for each of the spectrograph dipoles has a dump switch that must be armed to send current through the dipoles. The dump switch is in place to protect the conductors inside the cryostat from melting in the event that the magnet becomes non-superconducting while energized with high current. When triggered, a dump switch provides a high-current short circuit path to dump the energy from the magnet. The kinds of error conditions that will trigger the dump switches are the same conditions that trip off power supplies to other superconducting magnets on the beamlines. Examples include: a lead drop fault error, a quench detection (read and set values not agreeing over a period of time), a cryogenic error condition (e.g., a low helium level or blown rupture disk), and a loss in flow of cooling water for the power supplies. While designed to protect the magnet from a more expensive repair if the magnet quenches when energized, it is possible that the dump switch can get damaged if triggered because of the large amount of energy involved. Therefore, the magnet should be ramped down before any planned trigger conditions occur.
The Dump Switches of the two S800 dipoles are located in second level of S3 (see picture xxx). In order to arm the switches .xxxxx
Set S800 magnets currents to values of running setting
Open the Panel Mate screen THallps Turn on S800 magnets by clicking in the box with the corresponding name (e.g. I228DS), followed by a click in the ON box. (Go through pages xxx to cover all magnets.) Go to page xxx and select the steering magnets: ONLY THE S800, xxxxxx. Note that some of the power supplies are connected to more than one steering magnet. If necessary, disable the steering magnet of the other line and enable the correct one. Load setting: Open Barney Select S3, followed by S800 (see picture) For each of the three segments (segments 6, 7 and 8), enter value of magnetic rigidity and click on the button Set setting (see picture)
PREPARATION FOR TUNING In S3 vault
Arm dump switches Make sure object ion gauge is off
Go to page xx on Panel Mate xxx. Check status xxx Ensure viewer is ready
Make sure gas bottles for FP detectors are open Make sure Intermediate PPACs have gas
In data-U
Start Software tools PanelMates NMR GUIs Barney Labview Gas Handling System Controls Labview Bias Controls Alarm servers and monitors Linux HV controls (alarm server should be started first) SpecTcl (alart server should be started first) Run Control (in coordination with experimenters) Trigger Control GUI (in coordination with experimenters) Scalers (in coordination with experimenters) Put 10 Amps in Spectrograph dipoles
Start gas in detectors
Refer to Section xx (S800 Focal Plane Gas Handling System Operation)
Enable crad04 with a rate limit of 20 kHz (crad04 looks at E1 up) If it does not interfere with experimenter preparation (see “Unreacted Beam” section below) Set spectrograph Brho Start scalers
