In a medium saucepan set over medium-high heat, combine sugar, 1/2 tablespoon butter and 1/4 cup water. Clamp on a lid, bring to a boil, and cook for 7 minutes (the lid keeps sugar crystals from forming). Remove the lid, and continue to cook for 1 - 2 minutes until a golden caramel forms. Don't stir the mixture while it's cooking. Instead, occasionally gently swirl the pan to ensure even cooking. Take the mixture from the heat, and stir in the baking soda-salt-cayenne mixture. Immediately drizzle the caramel over the potato chips, using the 2 prepared spoons to toss. Transfer the topping to the prepared baking sheet, spreading it out in an even layer. Sprinkle with chopped thyme, and let cool completely before breaking into smaller pieces.