dear Dr. Aness, 

I think you can get a benefit from the below research in which we calculate the efficiency of the S.S.N.T.Ds.

Particle energy LET are important for determining the efficiency of SSNTD. In addition etching technique do influence the same. Use of some hydrogenious material around SSNTD increases efficiency. In the last nature or type of SSNTD material do influence. Last is the sensitivity of a given counting set up and techniques to counts criss-cross tracks.

The efficiency may depend on etching conditions (etching time, temperature, NaOH concentration) and counting of etched pits (tracks). 

https://www.ncbi.nlm.nih.gov/pubmed/20386194

https://www.ncbi.nlm.nih.gov/pubmed/4030336

Efforts have been made on the overlapping tracks due to high particle fluence.

https://www.ncbi.nlm.nih.gov/pubmed/26656081

https://www.ncbi.nlm.nih.gov/pubmed/25581623

Solid state nuclear track detectors are useful not only for dosimetry (e.g., of alpha particles from radon etc), but also for radiobiological experiments (e.g., by plating cultured cells onto CR-39 on one side, and by etching it on the other side, then the position of an ion hit within a cell population or even within a cell can be visualized).

https://www.researchgate.net/publication/51436194_Microbeam_Irradiation_Facilities_for_Radiobiology_in_Japan_and_China

https://www.researchgate.net/publication/3168434_Heavy-Ion_Microbeams-Development_and_Applications_in_Biological_Studies

Article Microbeam Irradiation Facilities for Radiobiology in Japan and China

Article Heavy-Ion Microbeams—Development and Applications in Biologi...

Thank you Dr. Nobuyuki Hamada for useful notes. 

Thank you Dr. Nada Farhan Kadhim for your comment and attached file. 

My pleasure, Dr Anees A. Al-Hamzawi

Thank you so much Dr. MUNISH KUMAR  for your comment and useful notes. 

Welcome Sir@Anees

Dear Dr.Aness

the document below contain the relation of calculating the efficiency.

https://www.sciencedirect.com/science/article/pii/0029554X72901036

The solid state nuclear track detector CR-39, together with a natural boron converter screen have been used as an

image-detector system for neutron radiography purposes. In order to determine its radiographic characteristics, the

image-detector system was irradiated up to neutron exposures around 6 -

1010 n/cm2 in a radiography facility

installed at the IEA-R1 Nuclear Research Reactor. The detectors were chemically etched in a KOH (30%) aqueous

solution at 708C. The best radiography conditions were obtained for neutron exposures ranging from 1 -

109 to

2 -

1010 n/cm2 and for 25 min etching time. The present results were compared with those determined for other

track detectors and discussed according to the theory of the image formation in solid state nuclear track detectors.

This theory is based on the optical properties of a single track. # 1999 Elsevier Science Ltd. All rights reserved.

Thank you so much Dr. Khulood Obaid for your comments and useful notes.

Thank you so much Dr. Nada Farhan Kadhim for the good work. Have a nice time

http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/25/019/25019093.pdf

1- The fulling Flux 2- Irradiation area from the surface of the detector 3- The distance from the radioactive source 4- Solid angle