How to construct a CS-137 cylindrical volume source?

1.I constructed the geometric model shown above to obtain the CS-137 energy spectrum,I wonder if the program is correct?Because I used MCNP to calculate the CS-137 count doesn’t seem so big.
2.Why is there still a 624keV peak in the spectrum

Cs-137-volume.flair (2.1 KB)
Cs-137-volume_17_tab.lis (45.1 KB)

Dear @fengfengxu,

I see that you are missing the DCYSCORE card in your input which is important if you want to set a USRBIN scoring card in your specific problem. Apart from that, the input seems to be correct.

When comparing your results obtained from different codes, please pay special attention to the way you are normalizing your data. Otherwise you may see important discrepancies. In order to do that, check in the manual the output units corresponding to your scoring cards.

Regarding the second question, what you see at around 624 keV are the peaks corresponding to the electron emission of 137Cs decay.

Hope this helps you.

Dear Expert,
Thanks for the expert’s answer. Your reply is helpful to me. Meanwhile, I solved this problem by referring to the example of Teacher David.I made two mistakes,for one thing, the probe setup material does not define Ge, Also, I used source.f to reset the location of the source.
Thank you expert,