UW CHEMISTRY NMR

Users had noticed that the lineshape on this instrument has been rather poor.  This is primarily due to the fact that the magnet is still taking its own time to settle down after the cryoshimming and B0 field adjustment approximately a month ago. Supercon Magnets are notoriously unpredictable when it comes to their expected duration before the main field and cryoshims are completely persistent.  It is not uncommon for even new magnets to take upto 3 months to settle down. Especially with DRX499 magnet’s history this behaviour is not surprising.  We will monitor the condition closely and keep up with re-shimming to provide you a usable shim set.   Attached below is the CHCl3 singlet from the lineshape standard, before and after the shimming operation. The curve in Red is with the starting shim distribution.  The system is eminently usable as of now.  Please do give your valuable feedback on noticeable changes.  Thank you