The following guidelines are for users who wish to apply for beamtime on the I11 facility (EH2) for long duration experiments. It is worth pointing out that such experiments represent a long term commitment of significant resources from users and beamline staff for the development (design, implementation and maintenance), operation and data analysis. In terms of duration, conception, delivery, data acquisition and logistics, LDEs are quite different from those of standard proposals.
Users should refer to the Technical Details
before considering a beamtime application. T
he key points and technical protocols for LDEs are as follows:
- The objective of LDE facility is for a class of experiments (LDEs) which are not accessible using conventional beamlines, but could greatly benefit from the use of synchrotron radiation for structural studies.
- The access route described here is for experiments which require synchrotron radiation powder diffraction data collected for a few weeks/months to 2 years.
- The call for LDE proposals is once a year and usually around Nov/Dec with a deadline in January.
- The new LDE hutch (I11 EH2) is designed to run a number of experiments with multiple stages for environments to keep samples under specific conditions (Technical Description).
- Users are expected to collaborate with beamline staff on LDE projects, particularly on the development of any new sample environments required.
- Users are not required to be on site for routine data collection (every Monday except in the machine shutdowns) which are managed by beamline staff, but they are expected be on site to assist with the initial setting up and to start the experiment.
- Experiment will run for an initial six months (trial period) after which a review will take place to justify continuation.
Users should also consult the guidelines for submitting proposals as for standard non-proprietary applications. LDE applications must be submitted via the UAS. A template for the six-month experimental report and justification for continuation of the LDE is also available in the UAS. Users intending to perform proprietary work should contact our Industrial Services.
Key stages of beamtime application
The keys stages to make an LDE application and for ongoing LDEs are shown schematically below. It is essential for the PI to consult with the beamline I11 team well before submission to assess feasibility, resource requirements and availability, and to agree on an initial technical rating (described below) for the proposed experiment. After submission, a final technical rating will be given to the peer review panel (PRP) to assist scientific assessment and scoring. The combined results will be presented to the Director of Physical Sciences to decide which LDEs should be approved in order to maximise resources and scientific output. The technical ratings (combining the design, construction and commissioning effort) are described in Figure 1 below.
Figure 1 - Key stages of new LDE applications from conception to delivery (blue path) and ongoing LDEs (green path)
All applications will be technically assessed and rated. The table below summarises the rating, description and estimated delivery time. The starting date for each approved LDE depends on the complexity of the sample environment ranging from one or two months (A) to 9 months or more (E). The official start date of an experiment will be when agreed specific experimental conditions are achieved. For those LDEs that have been running for six months or more, the PI is required to submit a report showing the progress and results so far to justify their continuation in the next PRP meeting irrespective of an LDE’s original proposed duration.
Table 1. Technical rating and the estimated time required to start a new experiment (delivery time)
Delivery time (months)
Easy - small amount of design effort should be needed, commissioning should be straightforward, or user’s own (working) cell requiring interfacing
Easy/difficult - some design effort, beamline team to assemble and commission the cell
Difficult - design effort, beamline staff to construct and commission the cell
Very difficult - significant design effort, construct and commissioning of the cell, may involve some research effort
Challenging - major design, construction effort and long lead time, research and also major commissioning
Unlikely to be successful
Suitability of Proposed Experiments
In contrast to the ultra-high resolution (MAC) and time-resolved (PSD) capability of EH1, the LDE facility is a medium resolution instrument (Δd/d ~ 10-3-10-4) which is useful to track or monitor significant changes in materials of interest, such as phase change and development, texture evolution and structural integrity/stability due to aging or non-ambient conditions (chemical corrosion, thermal and electrical cycling, etc.) With its poor contrast (no detector collimation), it is unsuitable for measuring tiny effects or subtle changes such as small lattice parameter changes, low phase concentration and profile analysis for micro-structural details. Here are a few LDE examples which have been successfully implemented and are currently running in I11 EH2.
- Nuclear - Hydration of cements used by the UK nuclear industry
- Battery Materials - Degradation of nano-FePO4 cathodes in Li-ion batteries and new cathode materials.
- Pharmaceuticals - Slow humidity effect on pharmaceuticals
- Gas capture & storage - Structural stability of metal-organic frameworks with loaded gases
- Geochemical processes – Mineral formation in cold aqueous environments
The application template can be downloaded from UAS
. Included in the application are the usual sections (abstract, scientific detail, results expected, etc.). Two final pieces of advice are:
- The panel are unlikely to award beamtime in absence of evidence that changes do actually happen over the period of the experiment. It is therefore essential to include data from complementary laboratory techniques such as IR, Raman, thermal analysis or XRD to justify beamtime.
- It is strongly recommended to discuss your proposed experiment with Prof. Chiu Tang (I11 Principal Beamline Scientist) and to do this well before the deadline for submission.