Written Documentation available

• A User Guide is available containing useful information on the sample environment, field, beam, etc...
  The guide is available in a PDF Version (2.0 Mbytes).
  
  
• Quick References are also available:
  
  
  • For the Quantum-cryostat 9505
    Postscript-format (1 Mbyte)
     
  • For the Quantum-cryostat 9506
    PDF-format (307 kbytes)
    Postscript-format (660 kbytes)
     
  • For the Quantum-cryostat 9512
    PDF-format (210 kbytes)
    Postscript-format (536 kbytes).
     
  
  
• A manual for the acquisition software deltat is available in HTML fomat or in PDF format
• A manual for the new electronics (so-called TDC-Electronics) is available in HTML fomat or in PDF format

General Specifications

• Location: area piM3.2 
• Positive muons, standard momentum: 28MeV/c)
• Muon polarization >95%
• Direction of spin ~6-60° with respect to muon momentum
• Positron detectors: 2 longitudinal, 3 transverse
• Look also here to obtain information on our Muon On REquest ("MORE") setup. 

Detector Arrangement 

• A muon detector (M) 
• Five positron detectors (with respect to the beam direction): 
• Forward (F) 
• Backward (B) 
• Up (U) 
• Down (D) 
• Right (R) 
• A Backward veto detector (B_veto).

This detector consists of a hollow scintillator pyramid with a 7x7 mm hole facing the M counter.
The purpose of B_veto is to collimate the muon beam to a 7x7 mm spot and to reject muons (and their decay positrons) missing the aperture ("active collimation"). 
• A forward veto detector (F_veto), rejecting muons which have not stopped in the sample (and their decay positrons). It is used with small samples. When the sample/holder assembly stops all muons, F_veto can be added to the F detector to increase the forward solid angle. 

• GIF:
  Vertical cross section (side view) (15kB);
  Vertical cross section (muon view) (15kB);
  Horizontal cross section (15kB). 


• PostScript:
  Vertical cross section (side view) (150kB);
  Vertical cross section (muon view) (150kB);
  Horizontal cross section (150kB). 

Sample Environment

• Type: Quantum Technology Corp. "top (or side) loading" continuous-flow He-4 evaporation cryostat. Sample in He-4 exchange gas. 
• Temperature Range 2-300K, liquid-He consumption approx. 2.5l/h at base temperature. (Liquid He comes in dewars with approx. 230 litres capacity). 
• Liquid He is supplied at regular intervals (Mondays and Fridays) at the filling station in the experimental hall (west gallery).
  While the orders for liquid He are placed by the instrument scientist, the users are expected to take care of the transport of the He dewars betweeen the filling station and the experimental area, to change them on the specified days and to return empty dewars immediately to the filling station.
• Two sample holders per cryostat allow fast sample change.
• Remote-controlled sample rotation (360°, rotation axis perpendicular to muon polarisation). 
• For the manual, please look into the GPS User Guide (PDF-format or Postscript-format) 

• Free diameter of the sample chamber: 23mm.
• Maximum sample length (including mount): 45mm.
• Sample region drawing available in GIF (12kB) or PostScript (80kB) format. 
• Sample holder platform as in the CCR and Janis cryostats of the GPD Instrument. Drawings of a possible sample mount are available here.
  For more details please contact the Instrument Scientist. 


• Please note:
  The users are expected to bring their own sample holders and make sure that the samples are safely sealed and fixed on the holder.
  Users who intend to bring hazardous sample materials (radioactive, toxic, flammable, etc.) to PSI should read the instructions on our safety page well in advance of their scheduled beam time.

CCR--4K

• Type: Janis with Sumitomo Heavy Industries Cold-Head:  "top (or side) loading".
• Sample in He-4 exchange gas when operated between 4K and 300K. 
• Used as a "warm finger" when operated between 300K and 475K.
• Installed on the 2nd cryogeny port.
• For the manual, please look into the GPS User Guide (PDF-format) 

Zürich Oven

• Type: Zürich University design.
• Used as a "warm finger" when operated between 300K and 1000K.
• For the manual, please look into the GPS User Guide (PDF-format) 

Magnetic Fields

• Main magnetic field (WED): 0-0.6T parallel to the beam
• Auxillary field (WEP): 0-10mT perpendicular to the beam

When performing experiments in zero-field mode, the compensation is done dynamically to ensure true zero-field conditions independently of the status of the external magnetic field sources.

When performing experiments in applied-field, the compensation is done according to tabulated values depending on the status of the external magnetic field sources.

Electronics / Data Aquisition

The users are responsible to store in a safe place their own data. Every week a backup of the data is performed in the PSI Archive system and the specific muSR ftp-server (see here for more information). 
You are strongly adviced to retrieve your data ("bin"-format) using our new ftp-server.

Logic

The area is equipped with a Experiment Console (running Scientific Linux) pc6012. The µSR data acquisition system hardware consists of this console and a Linux back-end server (psw405) located in the computing building (Hauptgebäude). This back-end is connected to a front-end PC running Windows-XP and controlling the PTA ORTEC 9308 Unit.
A number of different devices (temperature controlers, magnetic field power supplies, etc...) are used for the slow control of the experiment.
These devices are mainly controlled via GPIB (IEEE-488) bus or RS-232 serial line.

• GPIB :
  The GPIB devices are controlled through a Agilent LAN/GPIB Gateways (E2050A and the newest E5810A).
  
• RS-232 :
  The RS-232 devices are controlled through either a Agilent LAN/GPIB Gateways (E5810A) which supports one RS-232 line, or a Lantronix ETS8PS 8-channel RS232 terminal server

The acquisition software deltat is based entirely on the DAQ software package MIDAS.

Two Linux Workstations are also available and can be used through a usual ASF account or a local account (ask the instrument scientist for information). From these machines, one can connect also to the Linux cluster. 

The secondary beam-line control system controlling all beam-line elements (magnets, slit systems, separator etc.) between the target station and the experiment consists of a CAMAC crate containing the interfaces and modules needed for the beam line, a server PC (connected via RS232 to the CAMAC crate) and an area PC. The server and area PC's are connected via Ethernet. 
Area PC: Intel processor running under Windows XP.
 

Printers

Printing from Unix and Linux is now performed using the CUPS system. 

From the VAX workstation, to print ASCII files and Postscript files the command psprint should be used.

From UNIX/Linux-Cluster you can either use the glp command and choose the appropriate printer (WEHA_EG_1).
You can also set the environment variable PRINTER to be equal to the name of your printer, and use the lpr command.

For more information on CUPS, just look here. 

To print from a Windows Laptop, one should just install the corresponding printer:

Click the Start button and choose Run... option.
When prompted for a command just type \\winprintw
If a account and password is requested, just use "guest" as account and disregard the password by pressing ENTER
On the list choose the corresponding printer (WEHA_EG_1).
Right click and choose Install...

For more information, look here.

Finally one can also print local files directly from a browser using this link.