1. Production of a 3D-Printed THGEM Board
Omar Nour, Jerry Collins II
Faculty Advisor: Dr. Hohlmann, Dept of Aerospace, Physics, and Space Sciences, Florida Institute of Technology
Goals/Methods
Conclusion/Future work
Introduction
A gas electron multiplier (GEM) is a gaseous high energy particle detector that works by having an incident particle ionize the gas, which then creates an avalanche of ionization. This avalanche produces enough electrons to create a measurable current. Typical GEMs are made of 50-70µm thick insulating foil in between two layers of copper with holes about 30-70µm. GEMs are usually stacked in configurations to produce a desired gain. The thick GEM (THGEM) is a very similar technology that works in the same way as a standard GEM but about 5-20 times the dimensions. THGEMs are strong, low cost, easy to produce, and provide a high gain of electrons.
Our goal is to produce a working Thick GEM detector at lower cost, less sparking, and more efficient electron collection than the standard GEM. The THGEM can be produced from a variety of materials such as FR4 and Kevlar and it can be manufactured by standard drilling and etching of circuit boards. The holes are around 0.4-1mm (much larger than the standard GEM) with rims of around 0.1mm (shown in figure 3). The rims are important in reducing discharge and improving the gain. We attempted to 3D print a THGEM
Unfortunately, the board we received had a masking over the surface, different size holes, and unclearly defined to no rims. The holes were measured under a microscope and the sizes were observed to range from 0.5 – 1mm. We have yet to test this board due to an issue with a component in the detector but we’re currently attempting new techniques.
with 0.7mm holes and with three electrically isolated sectors with rim sizes 0, 0.1, and 0.18mm as shown in figure 4.
Figure 3: 0.4mm hole, 0.1mm rim.
Figure 5: The board we received had different sized holes and a visible insulating layer.
Figure 1: Typical GEM electrode. 50µm thick, 70µm hole diameter, 140µm pitch.
References
Chechik, R., Breskin, A., Shalem, C., Guedes, G., Cortesi, M., Dangendorf, V., Bar, D. (2005). A gaseous imaging detector based on thick GEM*-like (THGEM) multipliers [PPT]. Liverpool: PSD7.
Sauli, Fabio. (2016). The gas electron multiplier (GEM): Operating principles and applications. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment /j.nima
J. Collins II & M. Hohlmann, "The Design and Production of a 3D-Printed THGEM Board” 83rd Florida Academy of Sciences Meeting}, 2019.
Figure 4: 3D model of THGEM. 0.7mm holes and rim sizes of 0, 0.1, 0.18mm.
Figure 2: Triple stack GEM.