Developing #185
Updated by Sergey Belogurov over 6 years ago
<p>The shape of the target is not always planar. The target can be rotated around an axis (e.g vertical one) in order to face a telescope thus reducing the amount of material crossed by a reaction product. It is necessary to upgrade the algorithm which defines the interaction point inside the target. In the picture below</p>
<p>The target is black, its boundingbox is grey, the beam axis is lilac, the diagonal of the boundingbox is green, the path of an ion is orange. Thhe path inside the target is thick orange, it has the length -l. X- is the interaction point. X0 and x0+l - the points where the trajectory of an crosses the target boundary.</p>
<p>The interaction probability should depend on l. Convoluted wit the beam profile and angular distributiion it will give the correct distribution of th einteraction poins in space. If the nuclear interaction length is Lambda. The probability of the interaction th einteraction can be normalized to its maxilum possible value i.e. (1-exp(-A/Lambda)) </p> 1-exp(-A/Lambda)) </p>
<p> It is necessary to study how Vitaly uses the ROOT geometry navigation in reconstruction and generalize the definition of the interaction point for the complex (but convex) shape of the target. The case of thin target when the distribution of the interaction points along l is uniform, can be implemented first. </p>
<p><img alt="" data-rich-file-id="82" src="/develop/system/rich/rich_files/rich_files/000/000/082/original/target.png" /></p>
<p>Comments and questions are welcome!</p>
<p> </p>
<p>The target is black, its boundingbox is grey, the beam axis is lilac, the diagonal of the boundingbox is green, the path of an ion is orange. Thhe path inside the target is thick orange, it has the length -l. X- is the interaction point. X0 and x0+l - the points where the trajectory of an crosses the target boundary.</p>
<p>The interaction probability should depend on l. Convoluted wit the beam profile and angular distributiion it will give the correct distribution of th einteraction poins in space. If the nuclear interaction length is Lambda. The probability of the interaction th einteraction can be normalized to its maxilum possible value i.e. (1-exp(-A/Lambda)) </p> 1-exp(-A/Lambda)) </p>
<p> It is necessary to study how Vitaly uses the ROOT geometry navigation in reconstruction and generalize the definition of the interaction point for the complex (but convex) shape of the target. The case of thin target when the distribution of the interaction points along l is uniform, can be implemented first. </p>
<p><img alt="" data-rich-file-id="82" src="/develop/system/rich/rich_files/rich_files/000/000/082/original/target.png" /></p>
<p>Comments and questions are welcome!</p>
<p> </p>