Boca Research Muon Liquid Handling System User Manual

Muon Liquid Handling System

User Guide

C. Johnson, S.P. Cottrell et al

Version 0.2

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Contents

1 Getting Started 3

1.1 Layout of the liquid handling system 3

1.2 Layout of the in situ sample stick 4

1.3 Layout of the pump 4

2 General procedures 6

2.1 Sample loading 6

2.1.1 Loading Vessel 1 6

2.1.2 Loading Vessel 2 6

2.2 Evacuation of the system 6

2.2.1 Removing air from Vessel 1 7

2.2.2 Removing air from Vessel 2 7

2.2.3 Removing air from Vessel 3 7

2.2.4 Evacuation of the sample cell 7

2.3 Freeze-Pump-Thaw cycle 8

2.3.1 Sample in Vessel 1 8

2.3.2 Sample in Vessel 2 8

2.3.3 Sample in Vessel 3 9

2.4 Liquid transfers 9

2.4.1 Vessel 1 to sample cell 9

2.4.2 Vessel 3 to sample cell 10

2.4.3 Recovery of liquid in manifold to Vessel 2 10

2.4.4 Recovery of liquid in sample cell to Vessel 1 11

2.4.5 Recovery of liquid in sample cell to Vessel 2 11

2.4.6 Recovery of liquid in sample cell to Vessel 3 11

3 Example Experiment 13

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1 Getting Started

This manual describes the liquid handling system and the in situ sample cell as used
on the DEVA instrument with the “RF” spectrometer, for either normal muon spins
relaxation or RF resonance experiments.

1.1 Layout of the liquid handling system

The Muon Liquid Handling System has been designed to facilitate the in situ
degassing and transfer of samples into and out of the sample cell. The main features
of the liquid handling system are shown in Figure 1.

To pump

Inlet 1

Baratron

Vessel 1

Inlet 2

Vessel 2

Gas
pressure

Cell
pressure

Vessel 3

Figure 1 The layout of the front panel on the muon liquid handling system.

In general, the rig consists of three glass vessels for the storage of liquid samples, any
of which can be opened to a vacuum for the purposes of degassing by the freeze­pump-thaw method. Once degassed, the sample liquid can be transferred to the
sample cell contained within a cryostat without further exposure to the air. In
addition, samples may be returned to the rig for further freeze-pump-thaw cycles or
for disposal.

To cell

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1.2 Layout of the in situ sample stick

The liquid sample stick is designed to fit into the DEVA flow cryostat, details of
which can be found in the DEVA manual. It consists of a shapol target cell 30 mm x
30 mm with a mylar window upon which may be mounted an RF coil. Two stainless
steel capillaries provide a means of flowing liquid into and out of the cell along with
feed throughs for an RF excitation signal and a pick-up coil.

Figure 2 The liquid-sample cell mounted on a sample stick with a flat coil suitable for RF µSR.

1.3 Layout of the pump

The pump used with the Muon Liquid Handling System consists of a rotary pump
used to reduce the pressure of large volumes of gas and a turbo pump to achieve a
high vacuum. The main features pump used on the liquid handling system are shown
in the diagram below.

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Roughing/
Turbo

Off/Run
switch

Turbo
control panel

switch

Rotary
Pump

Pressure
reading

Turbo
Pump

Figure 2 The layout of the front panel on the vacuum pump used with the muon liquid handling

system.

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