10 Feb 2012




MERLIN Xpress is the new inelastic neutron scattering measurement-by-courier service for powder samples, using the high count-rate MERLIN spectrometer. 


MERLIN Xpress Access to beamtime at ISIS is suitable for:

  • new and infrequent users who want to test the feasibility of a potential MERLIN/LET/MARI experiment prior to submitting a full proposal.
  • research programmes requiring only limited and/or occasional neutron beamtime.
  • PhD students who need urgent data to complete their thesis.

A total of 2 beam days per proposal round will be devoted to this programme and it would be expected that each Xpress proposal may receive up to 1600 µAmps of proton current, which is approximately ten hours of beam time. The proposal can be submitted at any time and the experiment will be performed within the next two ISIS cycles. 

Experimental considerations

MERLIN Xpress will use Al-sample containers of 5 mm diameter.  This provides a sample volume of ~1 cm3.   Please send your samples to the MERLIN Express responsible (Dr Helen Walker,  Alternatively, if you wish to fill your sample yourself (e.g. air-sensitive or toxic samples) we will send sample cans to you in order that you can fill them and send back to Helen.  You should fill these to a maximum height of 50 mm (MERLIN beam height). 

Measurements will be performed at temperatures between 10K and 300K using the dedicated low temperature CCR.  The runs that should be performed on each sample can be added  in the ISIS online proposal system.

After the experiment, the samples/sample cans will be returned to you (where possible) so that you may recover your sample.  You are then responsible for sending the empty cans back to Helen Walker at ISIS.

Rules to follow:
a) Maximum 4 powder samples per proposal
b) Maximum 1500 μamps counting time per proposal (10 hours of beam time)
b) Incident energy ranges from 7meV to 1.5 eV
c) The MERLIN sloppy chopper will be used  - frequency range from 50 to 600 Hz
d) Temperature range between 10 K and 300 K

Data output

The data from MERLIN Xpress will be emailed to you on completion of the measurement.  The data format will be a standard ISIS .spe file, produced using Mantid.  You will have access to the raw data via the ISIS data catalog (

Data policy

Data collected using Xpress are subject to the normal ISIS policy regarding publication of scientific results, and bibliometric criteria, among others, will be used to assess the productivity of the scheme.