You want to compute
$$I=\int_0^X J_1( \alpha t)\,e^{-b t^2}\,dt$$
As you did, let $\alpha t=x$ to make
$$I={\frac 1 \alpha}\int_0^{ \alpha X} J_1( x)\,e^{-\beta x^2}\,dx \qquad \text{with}\qquad \beta=\frac{b}{\alpha^2 }$$
Now, use the expansion
$$ J_1( x)=\sum_{m=0}^\infty \frac{(-1)^m }{m! \,2^{2 m+1} \, \Gamma (m+2)}x^{2 m+1}$$ which makes that you face now the problem of
$$K_m=\int x^{2 m+1}\,e^{-\beta x^2}\,dx=-\frac{ \Gamma \left(m+1, \beta x^2\right) }{2\beta ^{(m+1)}} \,$$ and
$$L_m=\int_0^{ \alpha X} x^{2 m+1}\,e^{-\beta x^2}\,dx=\frac{\Gamma (m+1)-\Gamma \left(m+1,{ \beta \alpha ^2}X^2\right) }{2 \beta ^{m+1} }$$