Differences

This shows you the differences between two versions of the page.

--- focal_plane_unit [2025/05/27 22:19] – [Mechanical platform mount] 172.24.37.106
+++ focal_plane_unit [2025/05/30 18:07] (current) – 172.59.0.80
@@ Line 14: / Line 14: @@
 The iodine cell has been graciously provided by Dr. Paul Butler. It is numbered as "AS17" and is 4 inches long and 2 inches in diameter.
+The cell is heated along its length using corded xyx and then wrapped in ss for insulation ...
 The iodine cell is placed on a Thorlabs LTS150C motorized linear stage for moving it in and out of the optical path at the Nasmyth port. From the Windows desktop, this can be controlled with the Thorlabs Kinesis software, but normal usage for SONG is through the remote interface in APOsong.
 Temperature control is achieved using a Thorlabs TC300 controller with two heating elements for each half of the iodine cell. From the Windows desktop, this can be controlled with the Thorlabs TC300 software, but normal use for SONG is through the remote interface in APOsong.
+===== FPU calibration relay stage =====
+The calibration relay path on the FPU allows fiber fed calibration light to be fed back onto the science fiber via the Shelyak FIGU. The FPU layout allows the cal light to pass with or without passing through the iodine cell. The cal relay consists of a fixed set consisting of a 75mm 300m focal length acromat and a 75mm mirror plus a movable set of the same two elements using a Thorlabs LTS150 linear stage (same type as used for the moveable iodine cell).
+This a diagram of the FPU cal relay stage mechanical layout.
+{{:fpu:fpu_layout_diagram_may27.pdf|}}
+Here is a photo of the FPU during testing at APO in May 2025 with the new iodine cell holder and the cal relay stage.
+{{:fpu:fpu_apo_test_3.jpg?400|}}
 ===== Mechanical platform mount =====
@@ Line 23: / Line 37: @@
 The platform is 1/2 inch aluminum and anodized. It was manufactured at CVE Machine and Welding in High Rolls, NM.
-Here is a photo of the mount in the lab with an optical breadboard that holds the iodine cell, focusing and guiding unit, linear drives, and eventually calibration light input. {{ :fpu:mount_in_lab.jpg?direct&200|}}
+Here is a photo of the mount in the lab with an optical breadboard that holds the iodine cell, focusing and guiding unit, linear drives, and eventually calibration light input.
+{{:fpu:mount_in_lab.jpg?direct&300|}}
+Here is a photo of the PFU ,mounted on the 1m Nasmyth port for initial testing in Fall 2024.
+ {{:fpu:fpu_1m_oct2024.jpg?300|}}
 Documents
@@ Line 30: / Line 48: @@
-FPU calibration relay stage
-The calibration relay path on the FPU allows fiber fed calibration light to be fed back onto the science fiber via the Shelyak FIGU. The FPU layout allows the cal light to pass with or without passing through the iodine cell. The cal relay consists of a fixed set consisting of a 75mm 300m focal length acromat and a 75mm mirror plus a movable set of the same two elements using a Thorlabs LTS150 linear stage (same type as used for the moveable iodine cell).