GAMBE: a Gamma Blind Neutron Efficient Detector

Lead Research Organisation: University of Liverpool
Department Name: Physics


The project "GAMBE: a Gamma Blind Neutron Efficient Detector" aims to exploit the expertise acquired by the high energy physics group of the University of Liverpool in the development of state of the art silicon detector for particle physics to produce high efficiency neutron detectors with low background contamination, i.e. very low rates of spurious signals. These would be suitable for a wide range of applications, replacing detectors, but also offering significant additional capability.


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Description The project has three main goals described in the proposal:
1) Demonstration of gamma-ray suppression and increase in neutron detection efficiency for silicon sensors with Li6F coating
2) Increase in the efficiency of the detector when using pure Li6 with respect to the Li6F
3) Increase in the efficiency when using multilayer detector

The full simulation of the 1st two configurations has been performed with the goal of optimizing the thickness of the Li6F and Li6 layers. The electronics and sensors were designed and manufactured. The detector with the Li6F layer has been produced and tested. The gamma-ray suppression in combination with high efficiency has been observed. The progress has been made in designing the detector with stable Li6 layer. Tests with the Li6 layer have shown higher efficiency in comparison to the Li6F. Multilayer detector has been simulated and the optimal number of layers has been determined. Preliminary tests with two layers show increase in the efficiency. Special shielding increases the efficiency and also adds directional capabilities which have been extensively tested.
Exploitation Route The working neutron silicon detector could be used in many applications especially when it is important to keep the gamma-rays under control. Also, our silicon detector should be less affected by the noise due to high temperature. The neutron detectors working at high temperatures could be used in oil exploration. The neutron detector also could be used in beam cancer therapy to measure the dose and tune the simulation.
Sectors Aerospace, Defence and Marine,Energy,Healthcare,Security and Diplomacy,Other

Description The neutron detector developed using this award allowed to start discussion with possible industrial partners about future research; apply for further funding and file patent application.
Description Ministry Of Defense (MOD) of the Arab Republic of Egypt scholarship
Amount £54,291 (GBP)
Organisation Ministry of Defence and Military Production (Egypt) 
Sector Public
Country Egypt
Start 09/2015 
End 08/2018
Description Liverpool EEE 
Organisation University of Liverpool
Department NMR Centre for Structural Biology
Country United Kingdom 
Sector Academic/University 
PI Contribution Dr Sergey Burdin and Prof Gianluigi Casse supervise Ahmed Omar who is a self-funded PhD student at Department of Electrical Engineering & Electronics. Ahmed is testing and improving the GAMBE detector.
Collaborator Contribution Dr Harm Van Zalinge from Department of Electrical Engineering & Electronics is also Ahmed's supervisor. Monthly meetings allow developing the program for future experiments.
Impact The publication resulted directly from this partnership. Collaboration of the Physics Department and the Department of Electrical Engineering & Electronics could also play an important role for future development of electronics for the GAMBE detector. PhD student Ahmed Ahmed currently provides the main effort on this project and he is very close to submitting his thesis. This collaboration is multi-disciplinary.
Start Year 2015
Description PPI 
Organisation Rutherford Health plc
Country United Kingdom 
Sector Private 
PI Contribution Tests of the GAMBE detector at the Rutherford Cancer Centre (South Wales) where the neutron dose from proton beam in water phantom has been measured.
Collaborator Contribution Access to the Rutherford Cancer Centre (South Wales) and operation of the proton beam in June 2018. One hour of beam time costs £6.6k. The access was for two days shared with water phantom measurements. The in-kind contribution has been calculated as £6.6 x 8 hours.
Impact Application for CLASP grant (reference number ST/S006508/1).
Start Year 2018
Description A radiation detection system, comprising first (810) and second (820) semiconductor detectors each arranged to output respective detection signals wherein the first and second detectors (810, 820) are separated by a neutron reactive material(830), wherein the neutron reactive material (830)is arranged, in response to neutron capture, to emit at least two charged reaction products in generally opposing directions such that a first reaction product is detected by the first detector (810) and a second reaction product is detected by the second detector(820), a control unit coupled to the detector, the control unit (110) being arranged to apply a bias voltage to the first and second detectors (810, 820) and to receive the detection signals output from the first and second detectors(810, 820), wherein the control unit (110) is arranged to apply a first bias voltage to the first and second detectors (810, 820) and to store information indicative of detection signals received from the first and second detectors (810, 820) at the first bias voltage, to apply a second bias voltage to the first and second detectors (810, 820) and to store information indicative of detection signals at the second bias voltage, and wherein the control unit (110) is arranged to determine whether detection signals corresponding to detection of the first and second reaction products are received within a predetermined period. 
IP Reference WO2016203265 
Protection Patent application published
Year Protection Granted 2016
Licensed No
Impact This development and the patent application create a basis for collaboration with companies producing detectors. Discussions with several companies are in progress.
Title Compact neutron detector for tissue equivalent phantom 
Description Simulation shows that neutrons from proton cancer therapy represent significant fraction of the secondary radiation. The GAMBE is well suited for measurements of neutrons in the tissue equivalent phantom developed by the University of Liverpool in partnership with Proton Partners International. It will measure the dose with unprecedented position resolution from protons, electrons, positrons and photons. Multilayer sandwich configuration improves the neutron detection efficiency due to increased effective thickness of the converter layer and background rejection through limited tracking capabilities. The GAMBE also has directional capabilities which would provide additional benefits for detailed study. Detectors which are currently used to measure the neutron background have sensitivity to other particles as well (for example, TLD-600 from ThermoFisher Scientific) and therefore subtraction of the background using similar detectors but without neutron conversion layer (TLD-700) is performed. This could lead to systematic uncertainties as the detectors without the neutron converter layer still have some neutron sensitivity, they are located in slightly different places and measurements could be performed not at the same time. The published results differ by up to two orders of magnitude as was shown by U.Schneider and R.Hälg in "The impact of neutrons in clinical proton therapy" (Front. Oncol. 5:235 (2015)). Therefore clearly improvements are needed in the neutron measurement techniques. Currently the simulation studies are being performed. The intention is to perform beam test studies which would enable applications for future funding. 
Type Diagnostic Tool - Imaging
Current Stage Of Development Initial development
Year Development Stage Completed 2018
Development Status Actively seeking support
Impact Development of this detector in partnership with PPI allow establishing stronger links and better understanding of needs in the proton cancer therapy leading to improvements in other areas as well. 
Title Sandwich neutron detector 
Description Silicon neutron detector with Li6 or Li6F thermal neutron converter has been developed. A double channel waveform readout system has been developed as well. The detector can work in the coincidence and "OR" modes which allows maximum flexibility in the suppression of the gamma background. 
Type Of Technology Detection Devices 
Year Produced 2015 
Impact The research of possible applications is in progress. This product has been key to submission of the application for the Industry-academia partnership - Kazakhstan Newton funding (awaiting decision). A patent has been filed on the basis of this product. 
Description Summer School on Neutron Detectors 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Lecture "Neutron detection techniques in high gamma background" has been given to audience of approximately 40 researchers which followed by a discussion.
Year(s) Of Engagement Activity 2018